Filepath: githubCode\docs\conf.py:

import packaging.version
from pallets_sphinx_themes import get_version
from pallets_sphinx_themes import ProjectLink

# Project --------------------------------------------------------------

project = "Flask"
copyright = "2010 Pallets"
author = "Pallets"
release, version = get_version("Flask")

# General --------------------------------------------------------------

master_doc = "index"
extensions = [
    "sphinx.ext.autodoc",
    "sphinx.ext.intersphinx",
    "sphinxcontrib.log_cabinet",
    "pallets_sphinx_themes",
    "sphinx_issues",
    "sphinx_tabs.tabs",
]
autodoc_typehints = "description"
intersphinx_mapping = {
    "python": ("https://docs.python.org/3/", None),
    "werkzeug": ("https://werkzeug.palletsprojects.com/", None),
    "click": ("https://click.palletsprojects.com/", None),
    "jinja": ("https://jinja.palletsprojects.com/", None),
    "itsdangerous": ("https://itsdangerous.palletsprojects.com/", None),
    "sqlalchemy": ("https://docs.sqlalchemy.org/", None),
    "wtforms": ("https://wtforms.readthedocs.io/", None),
    "blinker": ("https://blinker.readthedocs.io/", None),
}
issues_github_path = "pallets/flask"

# HTML -----------------------------------------------------------------

html_theme = "flask"
html_theme_options = {"index_sidebar_logo": False}
html_context = {
    "project_links": [
        ProjectLink("Donate", "https://palletsprojects.com/donate"),
        ProjectLink("PyPI Releases", "https://pypi.org/project/Flask/"),
        ProjectLink("Source Code", "https://github.com/pallets/flask/"),
        ProjectLink("Issue Tracker", "https://github.com/pallets/flask/issues/"),
        ProjectLink("Chat", "https://discord.gg/pallets"),
    ]
}
html_sidebars = {
    "index": ["project.html", "localtoc.html", "searchbox.html", "ethicalads.html"],
    "**": ["localtoc.html", "relations.html", "searchbox.html", "ethicalads.html"],
}
singlehtml_sidebars = {"index": ["project.html", "localtoc.html", "ethicalads.html"]}
html_static_path = ["_static"]
html_favicon = "_static/shortcut-icon.png"
html_logo = "_static/flask-vertical.png"
html_title = f"Flask Documentation ({version})"
html_show_sourcelink = False

# LaTeX ----------------------------------------------------------------

latex_documents = [(master_doc, f"Flask-{version}.tex", html_title, author, "manual")]

# Local Extensions -----------------------------------------------------


def github_link(name, rawtext, text, lineno, inliner, options=None, content=None):
    app = inliner.document.settings.env.app
    release = app.config.release
    base_url = "https://github.com/pallets/flask/tree/"

    if text.endswith(">"):
        words, text = text[:-1].rsplit("<", 1)
        words = words.strip()
    else:
        words = None

    if packaging.version.parse(release).is_devrelease:
        url = f"{base_url}main/{text}"
    else:
        url = f"{base_url}{release}/{text}"

    if words is None:
        words = url

    from docutils.nodes import reference
    from docutils.parsers.rst.roles import set_classes

    options = options or {}
    set_classes(options)
    node = reference(rawtext, words, refuri=url, **options)
    return [node], []


def setup(app):
    app.add_role("gh", github_link)


Filepath: githubCode\tests\conftest.py:

import os
import pkgutil
import sys

import pytest
from _pytest import monkeypatch

from flask import Flask
from flask.globals import request_ctx


@pytest.fixture(scope="session", autouse=True)
def _standard_os_environ():
    """Set up ``os.environ`` at the start of the test session to have
    standard values. Returns a list of operations that is used by
    :func:`._reset_os_environ` after each test.
    """
    mp = monkeypatch.MonkeyPatch()
    out = (
        (os.environ, "FLASK_ENV_FILE", monkeypatch.notset),
        (os.environ, "FLASK_APP", monkeypatch.notset),
        (os.environ, "FLASK_DEBUG", monkeypatch.notset),
        (os.environ, "FLASK_RUN_FROM_CLI", monkeypatch.notset),
        (os.environ, "WERKZEUG_RUN_MAIN", monkeypatch.notset),
    )

    for _, key, value in out:
        if value is monkeypatch.notset:
            mp.delenv(key, False)
        else:
            mp.setenv(key, value)

    yield out
    mp.undo()


@pytest.fixture(autouse=True)
def _reset_os_environ(monkeypatch, _standard_os_environ):
    """Reset ``os.environ`` to the standard environ after each test,
    in case a test changed something without cleaning up.
    """
    monkeypatch._setitem.extend(_standard_os_environ)


@pytest.fixture
def app():
    app = Flask("flask_test", root_path=os.path.dirname(__file__))
    app.config.update(
        TESTING=True,
        SECRET_KEY="test key",
    )
    return app


@pytest.fixture
def app_ctx(app):
    with app.app_context() as ctx:
        yield ctx


@pytest.fixture
def req_ctx(app):
    with app.test_request_context() as ctx:
        yield ctx


@pytest.fixture
def client(app):
    return app.test_client()


@pytest.fixture
def test_apps(monkeypatch):
    monkeypatch.syspath_prepend(os.path.join(os.path.dirname(__file__), "test_apps"))
    original_modules = set(sys.modules.keys())

    yield

    # Remove any imports cached during the test. Otherwise "import app"
    # will work in the next test even though it's no longer on the path.
    for key in sys.modules.keys() - original_modules:
        sys.modules.pop(key)


@pytest.fixture(autouse=True)
def leak_detector():
    yield

    # make sure we're not leaking a request context since we are
    # testing flask internally in debug mode in a few cases
    leaks = []
    while request_ctx:
        leaks.append(request_ctx._get_current_object())
        request_ctx.pop()

    assert leaks == []


@pytest.fixture(params=(True, False))
def limit_loader(request, monkeypatch):
    """Patch pkgutil.get_loader to give loader without get_filename or archive.

    This provides for tests where a system has custom loaders, e.g. Google App
    Engine's HardenedModulesHook, which have neither the `get_filename` method
    nor the `archive` attribute.

    This fixture will run the testcase twice, once with and once without the
    limitation/mock.
    """
    if not request.param:
        return

    class LimitedLoader:
        def __init__(self, loader):
            self.loader = loader

        def __getattr__(self, name):
            if name in {"archive", "get_filename"}:
                raise AttributeError(f"Mocking a loader which does not have {name!r}.")
            return getattr(self.loader, name)

    old_get_loader = pkgutil.get_loader

    def get_loader(*args, **kwargs):
        return LimitedLoader(old_get_loader(*args, **kwargs))

    monkeypatch.setattr(pkgutil, "get_loader", get_loader)


@pytest.fixture
def modules_tmp_path(tmp_path, monkeypatch):
    """A temporary directory added to sys.path."""
    rv = tmp_path / "modules_tmp"
    rv.mkdir()
    monkeypatch.syspath_prepend(os.fspath(rv))
    return rv


@pytest.fixture
def modules_tmp_path_prefix(modules_tmp_path, monkeypatch):
    monkeypatch.setattr(sys, "prefix", os.fspath(modules_tmp_path))
    return modules_tmp_path


@pytest.fixture
def site_packages(modules_tmp_path, monkeypatch):
    """Create a fake site-packages."""
    py_dir = f"python{sys.version_info.major}.{sys.version_info.minor}"
    rv = modules_tmp_path / "lib" / py_dir / "site-packages"
    rv.mkdir(parents=True)
    monkeypatch.syspath_prepend(os.fspath(rv))
    return rv


@pytest.fixture
def purge_module(request):
    def inner(name):
        request.addfinalizer(lambda: sys.modules.pop(name, None))

    return inner


Filepath: githubCode\tests\test_appctx.py:

import pytest

import flask
from flask.globals import app_ctx
from flask.globals import request_ctx


def test_basic_url_generation(app):
    app.config["SERVER_NAME"] = "localhost"
    app.config["PREFERRED_URL_SCHEME"] = "https"

    @app.route("/")
    def index():
        pass

    with app.app_context():
        rv = flask.url_for("index")
        assert rv == "https://localhost/"


def test_url_generation_requires_server_name(app):
    with app.app_context():
        with pytest.raises(RuntimeError):
            flask.url_for("index")


def test_url_generation_without_context_fails():
    with pytest.raises(RuntimeError):
        flask.url_for("index")


def test_request_context_means_app_context(app):
    with app.test_request_context():
        assert flask.current_app._get_current_object() is app
    assert not flask.current_app


def test_app_context_provides_current_app(app):
    with app.app_context():
        assert flask.current_app._get_current_object() is app
    assert not flask.current_app


def test_app_tearing_down(app):
    cleanup_stuff = []

    @app.teardown_appcontext
    def cleanup(exception):
        cleanup_stuff.append(exception)

    with app.app_context():
        pass

    assert cleanup_stuff == [None]


def test_app_tearing_down_with_previous_exception(app):
    cleanup_stuff = []

    @app.teardown_appcontext
    def cleanup(exception):
        cleanup_stuff.append(exception)

    try:
        raise Exception("dummy")
    except Exception:
        pass

    with app.app_context():
        pass

    assert cleanup_stuff == [None]


def test_app_tearing_down_with_handled_exception_by_except_block(app):
    cleanup_stuff = []

    @app.teardown_appcontext
    def cleanup(exception):
        cleanup_stuff.append(exception)

    with app.app_context():
        try:
            raise Exception("dummy")
        except Exception:
            pass

    assert cleanup_stuff == [None]


def test_app_tearing_down_with_handled_exception_by_app_handler(app, client):
    app.config["PROPAGATE_EXCEPTIONS"] = True
    cleanup_stuff = []

    @app.teardown_appcontext
    def cleanup(exception):
        cleanup_stuff.append(exception)

    @app.route("/")
    def index():
        raise Exception("dummy")

    @app.errorhandler(Exception)
    def handler(f):
        return flask.jsonify(str(f))

    with app.app_context():
        client.get("/")

    assert cleanup_stuff == [None]


def test_app_tearing_down_with_unhandled_exception(app, client):
    app.config["PROPAGATE_EXCEPTIONS"] = True
    cleanup_stuff = []

    @app.teardown_appcontext
    def cleanup(exception):
        cleanup_stuff.append(exception)

    @app.route("/")
    def index():
        raise ValueError("dummy")

    with pytest.raises(ValueError, match="dummy"):
        with app.app_context():
            client.get("/")

    assert len(cleanup_stuff) == 1
    assert isinstance(cleanup_stuff[0], ValueError)
    assert str(cleanup_stuff[0]) == "dummy"


def test_app_ctx_globals_methods(app, app_ctx):
    # get
    assert flask.g.get("foo") is None
    assert flask.g.get("foo", "bar") == "bar"
    # __contains__
    assert "foo" not in flask.g
    flask.g.foo = "bar"
    assert "foo" in flask.g
    # setdefault
    flask.g.setdefault("bar", "the cake is a lie")
    flask.g.setdefault("bar", "hello world")
    assert flask.g.bar == "the cake is a lie"
    # pop
    assert flask.g.pop("bar") == "the cake is a lie"
    with pytest.raises(KeyError):
        flask.g.pop("bar")
    assert flask.g.pop("bar", "more cake") == "more cake"
    # __iter__
    assert list(flask.g) == ["foo"]
    # __repr__
    assert repr(flask.g) == "<flask.g of 'flask_test'>"


def test_custom_app_ctx_globals_class(app):
    class CustomRequestGlobals:
        def __init__(self):
            self.spam = "eggs"

    app.app_ctx_globals_class = CustomRequestGlobals
    with app.app_context():
        assert flask.render_template_string("{{ g.spam }}") == "eggs"


def test_context_refcounts(app, client):
    called = []

    @app.teardown_request
    def teardown_req(error=None):
        called.append("request")

    @app.teardown_appcontext
    def teardown_app(error=None):
        called.append("app")

    @app.route("/")
    def index():
        with app_ctx:
            with request_ctx:
                pass

        assert flask.request.environ["werkzeug.request"] is not None
        return ""

    res = client.get("/")
    assert res.status_code == 200
    assert res.data == b""
    assert called == ["request", "app"]


def test_clean_pop(app):
    app.testing = False
    called = []

    @app.teardown_request
    def teardown_req(error=None):
        raise ZeroDivisionError

    @app.teardown_appcontext
    def teardown_app(error=None):
        called.append("TEARDOWN")

    with app.app_context():
        called.append(flask.current_app.name)

    assert called == ["flask_test", "TEARDOWN"]
    assert not flask.current_app


Filepath: githubCode\tests\test_async.py:

import asyncio

import pytest

from flask import Blueprint
from flask import Flask
from flask import request
from flask.views import MethodView
from flask.views import View

pytest.importorskip("asgiref")


class AppError(Exception):
    pass


class BlueprintError(Exception):
    pass


class AsyncView(View):
    methods = ["GET", "POST"]

    async def dispatch_request(self):
        await asyncio.sleep(0)
        return request.method


class AsyncMethodView(MethodView):
    async def get(self):
        await asyncio.sleep(0)
        return "GET"

    async def post(self):
        await asyncio.sleep(0)
        return "POST"


@pytest.fixture(name="async_app")
def _async_app():
    app = Flask(__name__)

    @app.route("/", methods=["GET", "POST"])
    @app.route("/home", methods=["GET", "POST"])
    async def index():
        await asyncio.sleep(0)
        return request.method

    @app.errorhandler(AppError)
    async def handle(_):
        return "", 412

    @app.route("/error")
    async def error():
        raise AppError()

    blueprint = Blueprint("bp", __name__)

    @blueprint.route("/", methods=["GET", "POST"])
    async def bp_index():
        await asyncio.sleep(0)
        return request.method

    @blueprint.errorhandler(BlueprintError)
    async def bp_handle(_):
        return "", 412

    @blueprint.route("/error")
    async def bp_error():
        raise BlueprintError()

    app.register_blueprint(blueprint, url_prefix="/bp")

    app.add_url_rule("/view", view_func=AsyncView.as_view("view"))
    app.add_url_rule("/methodview", view_func=AsyncMethodView.as_view("methodview"))

    return app


@pytest.mark.parametrize("path", ["/", "/home", "/bp/", "/view", "/methodview"])
def test_async_route(path, async_app):
    test_client = async_app.test_client()
    response = test_client.get(path)
    assert b"GET" in response.get_data()
    response = test_client.post(path)
    assert b"POST" in response.get_data()


@pytest.mark.parametrize("path", ["/error", "/bp/error"])
def test_async_error_handler(path, async_app):
    test_client = async_app.test_client()
    response = test_client.get(path)
    assert response.status_code == 412


def test_async_before_after_request():
    app_before_called = False
    app_after_called = False
    bp_before_called = False
    bp_after_called = False

    app = Flask(__name__)

    @app.route("/")
    def index():
        return ""

    @app.before_request
    async def before():
        nonlocal app_before_called
        app_before_called = True

    @app.after_request
    async def after(response):
        nonlocal app_after_called
        app_after_called = True
        return response

    blueprint = Blueprint("bp", __name__)

    @blueprint.route("/")
    def bp_index():
        return ""

    @blueprint.before_request
    async def bp_before():
        nonlocal bp_before_called
        bp_before_called = True

    @blueprint.after_request
    async def bp_after(response):
        nonlocal bp_after_called
        bp_after_called = True
        return response

    app.register_blueprint(blueprint, url_prefix="/bp")

    test_client = app.test_client()
    test_client.get("/")
    assert app_before_called
    assert app_after_called
    test_client.get("/bp/")
    assert bp_before_called
    assert bp_after_called


Filepath: githubCode\tests\test_basic.py:

import gc
import re
import uuid
import warnings
import weakref
from datetime import datetime
from datetime import timezone
from platform import python_implementation

import pytest
import werkzeug.serving
from markupsafe import Markup
from werkzeug.exceptions import BadRequest
from werkzeug.exceptions import Forbidden
from werkzeug.exceptions import NotFound
from werkzeug.http import parse_date
from werkzeug.routing import BuildError
from werkzeug.routing import RequestRedirect

import flask

require_cpython_gc = pytest.mark.skipif(
    python_implementation() != "CPython",
    reason="Requires CPython GC behavior",
)


def test_options_work(app, client):
    @app.route("/", methods=["GET", "POST"])
    def index():
        return "Hello World"

    rv = client.open("/", method="OPTIONS")
    assert sorted(rv.allow) == ["GET", "HEAD", "OPTIONS", "POST"]
    assert rv.data == b""


def test_options_on_multiple_rules(app, client):
    @app.route("/", methods=["GET", "POST"])
    def index():
        return "Hello World"

    @app.route("/", methods=["PUT"])
    def index_put():
        return "Aha!"

    rv = client.open("/", method="OPTIONS")
    assert sorted(rv.allow) == ["GET", "HEAD", "OPTIONS", "POST", "PUT"]


@pytest.mark.parametrize("method", ["get", "post", "put", "delete", "patch"])
def test_method_route(app, client, method):
    method_route = getattr(app, method)
    client_method = getattr(client, method)

    @method_route("/")
    def hello():
        return "Hello"

    assert client_method("/").data == b"Hello"


def test_method_route_no_methods(app):
    with pytest.raises(TypeError):
        app.get("/", methods=["GET", "POST"])


def test_provide_automatic_options_attr():
    app = flask.Flask(__name__)

    def index():
        return "Hello World!"

    index.provide_automatic_options = False
    app.route("/")(index)
    rv = app.test_client().open("/", method="OPTIONS")
    assert rv.status_code == 405

    app = flask.Flask(__name__)

    def index2():
        return "Hello World!"

    index2.provide_automatic_options = True
    app.route("/", methods=["OPTIONS"])(index2)
    rv = app.test_client().open("/", method="OPTIONS")
    assert sorted(rv.allow) == ["OPTIONS"]


def test_provide_automatic_options_kwarg(app, client):
    def index():
        return flask.request.method

    def more():
        return flask.request.method

    app.add_url_rule("/", view_func=index, provide_automatic_options=False)
    app.add_url_rule(
        "/more",
        view_func=more,
        methods=["GET", "POST"],
        provide_automatic_options=False,
    )
    assert client.get("/").data == b"GET"

    rv = client.post("/")
    assert rv.status_code == 405
    assert sorted(rv.allow) == ["GET", "HEAD"]

    rv = client.open("/", method="OPTIONS")
    assert rv.status_code == 405

    rv = client.head("/")
    assert rv.status_code == 200
    assert not rv.data  # head truncates
    assert client.post("/more").data == b"POST"
    assert client.get("/more").data == b"GET"

    rv = client.delete("/more")
    assert rv.status_code == 405
    assert sorted(rv.allow) == ["GET", "HEAD", "POST"]

    rv = client.open("/more", method="OPTIONS")
    assert rv.status_code == 405


def test_request_dispatching(app, client):
    @app.route("/")
    def index():
        return flask.request.method

    @app.route("/more", methods=["GET", "POST"])
    def more():
        return flask.request.method

    assert client.get("/").data == b"GET"
    rv = client.post("/")
    assert rv.status_code == 405
    assert sorted(rv.allow) == ["GET", "HEAD", "OPTIONS"]
    rv = client.head("/")
    assert rv.status_code == 200
    assert not rv.data  # head truncates
    assert client.post("/more").data == b"POST"
    assert client.get("/more").data == b"GET"
    rv = client.delete("/more")
    assert rv.status_code == 405
    assert sorted(rv.allow) == ["GET", "HEAD", "OPTIONS", "POST"]


def test_disallow_string_for_allowed_methods(app):
    with pytest.raises(TypeError):
        app.add_url_rule("/", methods="GET POST", endpoint="test")


def test_url_mapping(app, client):
    random_uuid4 = "7eb41166-9ebf-4d26-b771-ea3f54f8b383"

    def index():
        return flask.request.method

    def more():
        return flask.request.method

    def options():
        return random_uuid4

    app.add_url_rule("/", "index", index)
    app.add_url_rule("/more", "more", more, methods=["GET", "POST"])

    # Issue 1288: Test that automatic options are not added
    #             when non-uppercase 'options' in methods
    app.add_url_rule("/options", "options", options, methods=["options"])

    assert client.get("/").data == b"GET"
    rv = client.post("/")
    assert rv.status_code == 405
    assert sorted(rv.allow) == ["GET", "HEAD", "OPTIONS"]
    rv = client.head("/")
    assert rv.status_code == 200
    assert not rv.data  # head truncates
    assert client.post("/more").data == b"POST"
    assert client.get("/more").data == b"GET"
    rv = client.delete("/more")
    assert rv.status_code == 405
    assert sorted(rv.allow) == ["GET", "HEAD", "OPTIONS", "POST"]
    rv = client.open("/options", method="OPTIONS")
    assert rv.status_code == 200
    assert random_uuid4 in rv.data.decode("utf-8")


def test_werkzeug_routing(app, client):
    from werkzeug.routing import Rule
    from werkzeug.routing import Submount

    app.url_map.add(
        Submount("/foo", [Rule("/bar", endpoint="bar"), Rule("/", endpoint="index")])
    )

    def bar():
        return "bar"

    def index():
        return "index"

    app.view_functions["bar"] = bar
    app.view_functions["index"] = index

    assert client.get("/foo/").data == b"index"
    assert client.get("/foo/bar").data == b"bar"


def test_endpoint_decorator(app, client):
    from werkzeug.routing import Rule
    from werkzeug.routing import Submount

    app.url_map.add(
        Submount("/foo", [Rule("/bar", endpoint="bar"), Rule("/", endpoint="index")])
    )

    @app.endpoint("bar")
    def bar():
        return "bar"

    @app.endpoint("index")
    def index():
        return "index"

    assert client.get("/foo/").data == b"index"
    assert client.get("/foo/bar").data == b"bar"


def test_session(app, client):
    @app.route("/set", methods=["POST"])
    def set():
        assert not flask.session.accessed
        assert not flask.session.modified
        flask.session["value"] = flask.request.form["value"]
        assert flask.session.accessed
        assert flask.session.modified
        return "value set"

    @app.route("/get")
    def get():
        assert not flask.session.accessed
        assert not flask.session.modified
        v = flask.session.get("value", "None")
        assert flask.session.accessed
        assert not flask.session.modified
        return v

    assert client.post("/set", data={"value": "42"}).data == b"value set"
    assert client.get("/get").data == b"42"


def test_session_path(app, client):
    app.config.update(APPLICATION_ROOT="/foo")

    @app.route("/")
    def index():
        flask.session["testing"] = 42
        return "Hello World"

    rv = client.get("/", "http://example.com:8080/foo")
    assert "path=/foo" in rv.headers["set-cookie"].lower()


def test_session_using_application_root(app, client):
    class PrefixPathMiddleware:
        def __init__(self, app, prefix):
            self.app = app
            self.prefix = prefix

        def __call__(self, environ, start_response):
            environ["SCRIPT_NAME"] = self.prefix
            return self.app(environ, start_response)

    app.wsgi_app = PrefixPathMiddleware(app.wsgi_app, "/bar")
    app.config.update(APPLICATION_ROOT="/bar")

    @app.route("/")
    def index():
        flask.session["testing"] = 42
        return "Hello World"

    rv = client.get("/", "http://example.com:8080/")
    assert "path=/bar" in rv.headers["set-cookie"].lower()


def test_session_using_session_settings(app, client):
    app.config.update(
        SERVER_NAME="www.example.com:8080",
        APPLICATION_ROOT="/test",
        SESSION_COOKIE_DOMAIN=".example.com",
        SESSION_COOKIE_HTTPONLY=False,
        SESSION_COOKIE_SECURE=True,
        SESSION_COOKIE_SAMESITE="Lax",
        SESSION_COOKIE_PATH="/",
    )

    @app.route("/")
    def index():
        flask.session["testing"] = 42
        return "Hello World"

    @app.route("/clear")
    def clear():
        flask.session.pop("testing", None)
        return "Goodbye World"

    rv = client.get("/", "http://www.example.com:8080/test/")
    cookie = rv.headers["set-cookie"].lower()
    # or condition for Werkzeug < 2.3
    assert "domain=example.com" in cookie or "domain=.example.com" in cookie
    assert "path=/" in cookie
    assert "secure" in cookie
    assert "httponly" not in cookie
    assert "samesite" in cookie

    rv = client.get("/clear", "http://www.example.com:8080/test/")
    cookie = rv.headers["set-cookie"].lower()
    assert "session=;" in cookie
    # or condition for Werkzeug < 2.3
    assert "domain=example.com" in cookie or "domain=.example.com" in cookie
    assert "path=/" in cookie
    assert "secure" in cookie
    assert "samesite" in cookie


def test_session_using_samesite_attribute(app, client):
    @app.route("/")
    def index():
        flask.session["testing"] = 42
        return "Hello World"

    app.config.update(SESSION_COOKIE_SAMESITE="invalid")

    with pytest.raises(ValueError):
        client.get("/")

    app.config.update(SESSION_COOKIE_SAMESITE=None)
    rv = client.get("/")
    cookie = rv.headers["set-cookie"].lower()
    assert "samesite" not in cookie

    app.config.update(SESSION_COOKIE_SAMESITE="Strict")
    rv = client.get("/")
    cookie = rv.headers["set-cookie"].lower()
    assert "samesite=strict" in cookie

    app.config.update(SESSION_COOKIE_SAMESITE="Lax")
    rv = client.get("/")
    cookie = rv.headers["set-cookie"].lower()
    assert "samesite=lax" in cookie


def test_missing_session(app):
    app.secret_key = None

    def expect_exception(f, *args, **kwargs):
        e = pytest.raises(RuntimeError, f, *args, **kwargs)
        assert e.value.args and "session is unavailable" in e.value.args[0]

    with app.test_request_context():
        assert flask.session.get("missing_key") is None
        expect_exception(flask.session.__setitem__, "foo", 42)
        expect_exception(flask.session.pop, "foo")


def test_session_expiration(app, client):
    permanent = True

    @app.route("/")
    def index():
        flask.session["test"] = 42
        flask.session.permanent = permanent
        return ""

    @app.route("/test")
    def test():
        return str(flask.session.permanent)

    rv = client.get("/")
    assert "set-cookie" in rv.headers
    match = re.search(r"(?i)\bexpires=([^;]+)", rv.headers["set-cookie"])
    expires = parse_date(match.group())
    expected = datetime.now(timezone.utc) + app.permanent_session_lifetime
    assert expires.year == expected.year
    assert expires.month == expected.month
    assert expires.day == expected.day

    rv = client.get("/test")
    assert rv.data == b"True"

    permanent = False
    rv = client.get("/")
    assert "set-cookie" in rv.headers
    match = re.search(r"\bexpires=([^;]+)", rv.headers["set-cookie"])
    assert match is None


def test_session_stored_last(app, client):
    @app.after_request
    def modify_session(response):
        flask.session["foo"] = 42
        return response

    @app.route("/")
    def dump_session_contents():
        return repr(flask.session.get("foo"))

    assert client.get("/").data == b"None"
    assert client.get("/").data == b"42"


def test_session_special_types(app, client):
    now = datetime.now(timezone.utc).replace(microsecond=0)
    the_uuid = uuid.uuid4()

    @app.route("/")
    def dump_session_contents():
        flask.session["t"] = (1, 2, 3)
        flask.session["b"] = b"\xff"
        flask.session["m"] = Markup("<html>")
        flask.session["u"] = the_uuid
        flask.session["d"] = now
        flask.session["t_tag"] = {" t": "not-a-tuple"}
        flask.session["di_t_tag"] = {" t__": "not-a-tuple"}
        flask.session["di_tag"] = {" di": "not-a-dict"}
        return "", 204

    with client:
        client.get("/")
        s = flask.session
        assert s["t"] == (1, 2, 3)
        assert type(s["b"]) is bytes  # noqa: E721
        assert s["b"] == b"\xff"
        assert type(s["m"]) is Markup  # noqa: E721
        assert s["m"] == Markup("<html>")
        assert s["u"] == the_uuid
        assert s["d"] == now
        assert s["t_tag"] == {" t": "not-a-tuple"}
        assert s["di_t_tag"] == {" t__": "not-a-tuple"}
        assert s["di_tag"] == {" di": "not-a-dict"}


def test_session_cookie_setting(app):
    is_permanent = True

    @app.route("/bump")
    def bump():
        rv = flask.session["foo"] = flask.session.get("foo", 0) + 1
        flask.session.permanent = is_permanent
        return str(rv)

    @app.route("/read")
    def read():
        return str(flask.session.get("foo", 0))

    def run_test(expect_header):
        with app.test_client() as c:
            assert c.get("/bump").data == b"1"
            assert c.get("/bump").data == b"2"
            assert c.get("/bump").data == b"3"

            rv = c.get("/read")
            set_cookie = rv.headers.get("set-cookie")
            assert (set_cookie is not None) == expect_header
            assert rv.data == b"3"

    is_permanent = True
    app.config["SESSION_REFRESH_EACH_REQUEST"] = True
    run_test(expect_header=True)

    is_permanent = True
    app.config["SESSION_REFRESH_EACH_REQUEST"] = False
    run_test(expect_header=False)

    is_permanent = False
    app.config["SESSION_REFRESH_EACH_REQUEST"] = True
    run_test(expect_header=False)

    is_permanent = False
    app.config["SESSION_REFRESH_EACH_REQUEST"] = False
    run_test(expect_header=False)


def test_session_vary_cookie(app, client):
    @app.route("/set")
    def set_session():
        flask.session["test"] = "test"
        return ""

    @app.route("/get")
    def get():
        return flask.session.get("test")

    @app.route("/getitem")
    def getitem():
        return flask.session["test"]

    @app.route("/setdefault")
    def setdefault():
        return flask.session.setdefault("test", "default")

    @app.route("/clear")
    def clear():
        flask.session.clear()
        return ""

    @app.route("/vary-cookie-header-set")
    def vary_cookie_header_set():
        response = flask.Response()
        response.vary.add("Cookie")
        flask.session["test"] = "test"
        return response

    @app.route("/vary-header-set")
    def vary_header_set():
        response = flask.Response()
        response.vary.update(("Accept-Encoding", "Accept-Language"))
        flask.session["test"] = "test"
        return response

    @app.route("/no-vary-header")
    def no_vary_header():
        return ""

    def expect(path, header_value="Cookie"):
        rv = client.get(path)

        if header_value:
            # The 'Vary' key should exist in the headers only once.
            assert len(rv.headers.get_all("Vary")) == 1
            assert rv.headers["Vary"] == header_value
        else:
            assert "Vary" not in rv.headers

    expect("/set")
    expect("/get")
    expect("/getitem")
    expect("/setdefault")
    expect("/clear")
    expect("/vary-cookie-header-set")
    expect("/vary-header-set", "Accept-Encoding, Accept-Language, Cookie")
    expect("/no-vary-header", None)


def test_session_refresh_vary(app, client):
    @app.get("/login")
    def login():
        flask.session["user_id"] = 1
        flask.session.permanent = True
        return ""

    @app.get("/ignored")
    def ignored():
        return ""

    rv = client.get("/login")
    assert rv.headers["Vary"] == "Cookie"
    rv = client.get("/ignored")
    assert rv.headers["Vary"] == "Cookie"


def test_flashes(app, req_ctx):
    assert not flask.session.modified
    flask.flash("Zap")
    flask.session.modified = False
    flask.flash("Zip")
    assert flask.session.modified
    assert list(flask.get_flashed_messages()) == ["Zap", "Zip"]


def test_extended_flashing(app):
    # Be sure app.testing=True below, else tests can fail silently.
    #
    # Specifically, if app.testing is not set to True, the AssertionErrors
    # in the view functions will cause a 500 response to the test client
    # instead of propagating exceptions.

    @app.route("/")
    def index():
        flask.flash("Hello World")
        flask.flash("Hello World", "error")
        flask.flash(Markup("<em>Testing</em>"), "warning")
        return ""

    @app.route("/test/")
    def test():
        messages = flask.get_flashed_messages()
        assert list(messages) == [
            "Hello World",
            "Hello World",
            Markup("<em>Testing</em>"),
        ]
        return ""

    @app.route("/test_with_categories/")
    def test_with_categories():
        messages = flask.get_flashed_messages(with_categories=True)
        assert len(messages) == 3
        assert list(messages) == [
            ("message", "Hello World"),
            ("error", "Hello World"),
            ("warning", Markup("<em>Testing</em>")),
        ]
        return ""

    @app.route("/test_filter/")
    def test_filter():
        messages = flask.get_flashed_messages(
            category_filter=["message"], with_categories=True
        )
        assert list(messages) == [("message", "Hello World")]
        return ""

    @app.route("/test_filters/")
    def test_filters():
        messages = flask.get_flashed_messages(
            category_filter=["message", "warning"], with_categories=True
        )
        assert list(messages) == [
            ("message", "Hello World"),
            ("warning", Markup("<em>Testing</em>")),
        ]
        return ""

    @app.route("/test_filters_without_returning_categories/")
    def test_filters2():
        messages = flask.get_flashed_messages(category_filter=["message", "warning"])
        assert len(messages) == 2
        assert messages[0] == "Hello World"
        assert messages[1] == Markup("<em>Testing</em>")
        return ""

    # Create new test client on each test to clean flashed messages.

    client = app.test_client()
    client.get("/")
    client.get("/test_with_categories/")

    client = app.test_client()
    client.get("/")
    client.get("/test_filter/")

    client = app.test_client()
    client.get("/")
    client.get("/test_filters/")

    client = app.test_client()
    client.get("/")
    client.get("/test_filters_without_returning_categories/")


def test_request_processing(app, client):
    evts = []

    @app.before_request
    def before_request():
        evts.append("before")

    @app.after_request
    def after_request(response):
        response.data += b"|after"
        evts.append("after")
        return response

    @app.route("/")
    def index():
        assert "before" in evts
        assert "after" not in evts
        return "request"

    assert "after" not in evts
    rv = client.get("/").data
    assert "after" in evts
    assert rv == b"request|after"


def test_request_preprocessing_early_return(app, client):
    evts = []

    @app.before_request
    def before_request1():
        evts.append(1)

    @app.before_request
    def before_request2():
        evts.append(2)
        return "hello"

    @app.before_request
    def before_request3():
        evts.append(3)
        return "bye"

    @app.route("/")
    def index():
        evts.append("index")
        return "damnit"

    rv = client.get("/").data.strip()
    assert rv == b"hello"
    assert evts == [1, 2]


def test_after_request_processing(app, client):
    @app.route("/")
    def index():
        @flask.after_this_request
        def foo(response):
            response.headers["X-Foo"] = "a header"
            return response

        return "Test"

    resp = client.get("/")
    assert resp.status_code == 200
    assert resp.headers["X-Foo"] == "a header"


def test_teardown_request_handler(app, client):
    called = []

    @app.teardown_request
    def teardown_request(exc):
        called.append(True)
        return "Ignored"

    @app.route("/")
    def root():
        return "Response"

    rv = client.get("/")
    assert rv.status_code == 200
    assert b"Response" in rv.data
    assert len(called) == 1


def test_teardown_request_handler_debug_mode(app, client):
    called = []

    @app.teardown_request
    def teardown_request(exc):
        called.append(True)
        return "Ignored"

    @app.route("/")
    def root():
        return "Response"

    rv = client.get("/")
    assert rv.status_code == 200
    assert b"Response" in rv.data
    assert len(called) == 1


def test_teardown_request_handler_error(app, client):
    called = []
    app.testing = False

    @app.teardown_request
    def teardown_request1(exc):
        assert type(exc) is ZeroDivisionError
        called.append(True)
        # This raises a new error and blows away sys.exc_info(), so we can
        # test that all teardown_requests get passed the same original
        # exception.
        try:
            raise TypeError()
        except Exception:
            pass

    @app.teardown_request
    def teardown_request2(exc):
        assert type(exc) is ZeroDivisionError
        called.append(True)
        # This raises a new error and blows away sys.exc_info(), so we can
        # test that all teardown_requests get passed the same original
        # exception.
        try:
            raise TypeError()
        except Exception:
            pass

    @app.route("/")
    def fails():
        raise ZeroDivisionError

    rv = client.get("/")
    assert rv.status_code == 500
    assert b"Internal Server Error" in rv.data
    assert len(called) == 2


def test_before_after_request_order(app, client):
    called = []

    @app.before_request
    def before1():
        called.append(1)

    @app.before_request
    def before2():
        called.append(2)

    @app.after_request
    def after1(response):
        called.append(4)
        return response

    @app.after_request
    def after2(response):
        called.append(3)
        return response

    @app.teardown_request
    def finish1(exc):
        called.append(6)

    @app.teardown_request
    def finish2(exc):
        called.append(5)

    @app.route("/")
    def index():
        return "42"

    rv = client.get("/")
    assert rv.data == b"42"
    assert called == [1, 2, 3, 4, 5, 6]


def test_error_handling(app, client):
    app.testing = False

    @app.errorhandler(404)
    def not_found(e):
        return "not found", 404

    @app.errorhandler(500)
    def internal_server_error(e):
        return "internal server error", 500

    @app.errorhandler(Forbidden)
    def forbidden(e):
        return "forbidden", 403

    @app.route("/")
    def index():
        flask.abort(404)

    @app.route("/error")
    def error():
        raise ZeroDivisionError

    @app.route("/forbidden")
    def error2():
        flask.abort(403)

    rv = client.get("/")
    assert rv.status_code == 404
    assert rv.data == b"not found"
    rv = client.get("/error")
    assert rv.status_code == 500
    assert b"internal server error" == rv.data
    rv = client.get("/forbidden")
    assert rv.status_code == 403
    assert b"forbidden" == rv.data


def test_error_handling_processing(app, client):
    app.testing = False

    @app.errorhandler(500)
    def internal_server_error(e):
        return "internal server error", 500

    @app.route("/")
    def broken_func():
        raise ZeroDivisionError

    @app.after_request
    def after_request(resp):
        resp.mimetype = "text/x-special"
        return resp

    resp = client.get("/")
    assert resp.mimetype == "text/x-special"
    assert resp.data == b"internal server error"


def test_baseexception_error_handling(app, client):
    app.testing = False

    @app.route("/")
    def broken_func():
        raise KeyboardInterrupt()

    with pytest.raises(KeyboardInterrupt):
        client.get("/")


def test_before_request_and_routing_errors(app, client):
    @app.before_request
    def attach_something():
        flask.g.something = "value"

    @app.errorhandler(404)
    def return_something(error):
        return flask.g.something, 404

    rv = client.get("/")
    assert rv.status_code == 404
    assert rv.data == b"value"


def test_user_error_handling(app, client):
    class MyException(Exception):
        pass

    @app.errorhandler(MyException)
    def handle_my_exception(e):
        assert isinstance(e, MyException)
        return "42"

    @app.route("/")
    def index():
        raise MyException()

    assert client.get("/").data == b"42"


def test_http_error_subclass_handling(app, client):
    class ForbiddenSubclass(Forbidden):
        pass

    @app.errorhandler(ForbiddenSubclass)
    def handle_forbidden_subclass(e):
        assert isinstance(e, ForbiddenSubclass)
        return "banana"

    @app.errorhandler(403)
    def handle_403(e):
        assert not isinstance(e, ForbiddenSubclass)
        assert isinstance(e, Forbidden)
        return "apple"

    @app.route("/1")
    def index1():
        raise ForbiddenSubclass()

    @app.route("/2")
    def index2():
        flask.abort(403)

    @app.route("/3")
    def index3():
        raise Forbidden()

    assert client.get("/1").data == b"banana"
    assert client.get("/2").data == b"apple"
    assert client.get("/3").data == b"apple"


def test_errorhandler_precedence(app, client):
    class E1(Exception):
        pass

    class E2(Exception):
        pass

    class E3(E1, E2):
        pass

    @app.errorhandler(E2)
    def handle_e2(e):
        return "E2"

    @app.errorhandler(Exception)
    def handle_exception(e):
        return "Exception"

    @app.route("/E1")
    def raise_e1():
        raise E1

    @app.route("/E3")
    def raise_e3():
        raise E3

    rv = client.get("/E1")
    assert rv.data == b"Exception"

    rv = client.get("/E3")
    assert rv.data == b"E2"


@pytest.mark.parametrize(
    ("debug", "trap", "expect_key", "expect_abort"),
    [(False, None, True, True), (True, None, False, True), (False, True, False, False)],
)
def test_trap_bad_request_key_error(app, client, debug, trap, expect_key, expect_abort):
    app.config["DEBUG"] = debug
    app.config["TRAP_BAD_REQUEST_ERRORS"] = trap

    @app.route("/key")
    def fail():
        flask.request.form["missing_key"]

    @app.route("/abort")
    def allow_abort():
        flask.abort(400)

    if expect_key:
        rv = client.get("/key")
        assert rv.status_code == 400
        assert b"missing_key" not in rv.data
    else:
        with pytest.raises(KeyError) as exc_info:
            client.get("/key")

        assert exc_info.errisinstance(BadRequest)
        assert "missing_key" in exc_info.value.get_description()

    if expect_abort:
        rv = client.get("/abort")
        assert rv.status_code == 400
    else:
        with pytest.raises(BadRequest):
            client.get("/abort")


def test_trapping_of_all_http_exceptions(app, client):
    app.config["TRAP_HTTP_EXCEPTIONS"] = True

    @app.route("/fail")
    def fail():
        flask.abort(404)

    with pytest.raises(NotFound):
        client.get("/fail")


def test_error_handler_after_processor_error(app, client):
    app.testing = False

    @app.before_request
    def before_request():
        if _trigger == "before":
            raise ZeroDivisionError

    @app.after_request
    def after_request(response):
        if _trigger == "after":
            raise ZeroDivisionError

        return response

    @app.route("/")
    def index():
        return "Foo"

    @app.errorhandler(500)
    def internal_server_error(e):
        return "Hello Server Error", 500

    for _trigger in "before", "after":
        rv = client.get("/")
        assert rv.status_code == 500
        assert rv.data == b"Hello Server Error"


def test_enctype_debug_helper(app, client):
    from flask.debughelpers import DebugFilesKeyError

    app.debug = True

    @app.route("/fail", methods=["POST"])
    def index():
        return flask.request.files["foo"].filename

    with pytest.raises(DebugFilesKeyError) as e:
        client.post("/fail", data={"foo": "index.txt"})
    assert "no file contents were transmitted" in str(e.value)
    assert "This was submitted: 'index.txt'" in str(e.value)


def test_response_types(app, client):
    @app.route("/text")
    def from_text():
        return "Hällo Wörld"

    @app.route("/bytes")
    def from_bytes():
        return "Hällo Wörld".encode()

    @app.route("/full_tuple")
    def from_full_tuple():
        return (
            "Meh",
            400,
            {"X-Foo": "Testing", "Content-Type": "text/plain; charset=utf-8"},
        )

    @app.route("/text_headers")
    def from_text_headers():
        return "Hello", {"X-Foo": "Test", "Content-Type": "text/plain; charset=utf-8"}

    @app.route("/text_status")
    def from_text_status():
        return "Hi, status!", 400

    @app.route("/response_headers")
    def from_response_headers():
        return (
            flask.Response(
                "Hello world", 404, {"Content-Type": "text/html", "X-Foo": "Baz"}
            ),
            {"Content-Type": "text/plain", "X-Foo": "Bar", "X-Bar": "Foo"},
        )

    @app.route("/response_status")
    def from_response_status():
        return app.response_class("Hello world", 400), 500

    @app.route("/wsgi")
    def from_wsgi():
        return NotFound()

    @app.route("/dict")
    def from_dict():
        return {"foo": "bar"}, 201

    @app.route("/list")
    def from_list():
        return ["foo", "bar"], 201

    assert client.get("/text").data == "Hällo Wörld".encode()
    assert client.get("/bytes").data == "Hällo Wörld".encode()

    rv = client.get("/full_tuple")
    assert rv.data == b"Meh"
    assert rv.headers["X-Foo"] == "Testing"
    assert rv.status_code == 400
    assert rv.mimetype == "text/plain"

    rv = client.get("/text_headers")
    assert rv.data == b"Hello"
    assert rv.headers["X-Foo"] == "Test"
    assert rv.status_code == 200
    assert rv.mimetype == "text/plain"

    rv = client.get("/text_status")
    assert rv.data == b"Hi, status!"
    assert rv.status_code == 400
    assert rv.mimetype == "text/html"

    rv = client.get("/response_headers")
    assert rv.data == b"Hello world"
    assert rv.content_type == "text/plain"
    assert rv.headers.getlist("X-Foo") == ["Bar"]
    assert rv.headers["X-Bar"] == "Foo"
    assert rv.status_code == 404

    rv = client.get("/response_status")
    assert rv.data == b"Hello world"
    assert rv.status_code == 500

    rv = client.get("/wsgi")
    assert b"Not Found" in rv.data
    assert rv.status_code == 404

    rv = client.get("/dict")
    assert rv.json == {"foo": "bar"}
    assert rv.status_code == 201

    rv = client.get("/list")
    assert rv.json == ["foo", "bar"]
    assert rv.status_code == 201


def test_response_type_errors():
    app = flask.Flask(__name__)
    app.testing = True

    @app.route("/none")
    def from_none():
        pass

    @app.route("/small_tuple")
    def from_small_tuple():
        return ("Hello",)

    @app.route("/large_tuple")
    def from_large_tuple():
        return "Hello", 234, {"X-Foo": "Bar"}, "???"

    @app.route("/bad_type")
    def from_bad_type():
        return True

    @app.route("/bad_wsgi")
    def from_bad_wsgi():
        return lambda: None

    c = app.test_client()

    with pytest.raises(TypeError) as e:
        c.get("/none")

    assert "returned None" in str(e.value)
    assert "from_none" in str(e.value)

    with pytest.raises(TypeError) as e:
        c.get("/small_tuple")

    assert "tuple must have the form" in str(e.value)

    with pytest.raises(TypeError):
        c.get("/large_tuple")

    with pytest.raises(TypeError) as e:
        c.get("/bad_type")

    assert "it was a bool" in str(e.value)

    with pytest.raises(TypeError):
        c.get("/bad_wsgi")


def test_make_response(app, req_ctx):
    rv = flask.make_response()
    assert rv.status_code == 200
    assert rv.data == b""
    assert rv.mimetype == "text/html"

    rv = flask.make_response("Awesome")
    assert rv.status_code == 200
    assert rv.data == b"Awesome"
    assert rv.mimetype == "text/html"

    rv = flask.make_response("W00t", 404)
    assert rv.status_code == 404
    assert rv.data == b"W00t"
    assert rv.mimetype == "text/html"

    rv = flask.make_response(c for c in "Hello")
    assert rv.status_code == 200
    assert rv.data == b"Hello"
    assert rv.mimetype == "text/html"


def test_make_response_with_response_instance(app, req_ctx):
    rv = flask.make_response(flask.jsonify({"msg": "W00t"}), 400)
    assert rv.status_code == 400
    assert rv.data == b'{"msg":"W00t"}\n'
    assert rv.mimetype == "application/json"

    rv = flask.make_response(flask.Response(""), 400)
    assert rv.status_code == 400
    assert rv.data == b""
    assert rv.mimetype == "text/html"

    rv = flask.make_response(
        flask.Response("", headers={"Content-Type": "text/html"}),
        400,
        [("X-Foo", "bar")],
    )
    assert rv.status_code == 400
    assert rv.headers["Content-Type"] == "text/html"
    assert rv.headers["X-Foo"] == "bar"


@pytest.mark.parametrize("compact", [True, False])
def test_jsonify_no_prettyprint(app, compact):
    app.json.compact = compact
    rv = app.json.response({"msg": {"submsg": "W00t"}, "msg2": "foobar"})
    data = rv.data.strip()
    assert (b" " not in data) is compact
    assert (b"\n" not in data) is compact


def test_jsonify_mimetype(app, req_ctx):
    app.json.mimetype = "application/vnd.api+json"
    msg = {"msg": {"submsg": "W00t"}}
    rv = flask.make_response(flask.jsonify(msg), 200)
    assert rv.mimetype == "application/vnd.api+json"


def test_json_dump_dataclass(app, req_ctx):
    from dataclasses import make_dataclass

    Data = make_dataclass("Data", [("name", str)])
    value = app.json.dumps(Data("Flask"))
    value = app.json.loads(value)
    assert value == {"name": "Flask"}


def test_jsonify_args_and_kwargs_check(app, req_ctx):
    with pytest.raises(TypeError) as e:
        flask.jsonify("fake args", kwargs="fake")
    assert "args or kwargs" in str(e.value)


def test_url_generation(app, req_ctx):
    @app.route("/hello/<name>", methods=["POST"])
    def hello():
        pass

    assert flask.url_for("hello", name="test x") == "/hello/test%20x"
    assert (
        flask.url_for("hello", name="test x", _external=True)
        == "http://localhost/hello/test%20x"
    )


def test_build_error_handler(app):
    # Test base case, a URL which results in a BuildError.
    with app.test_request_context():
        pytest.raises(BuildError, flask.url_for, "spam")

    # Verify the error is re-raised if not the current exception.
    try:
        with app.test_request_context():
            flask.url_for("spam")
    except BuildError as err:
        error = err
    try:
        raise RuntimeError("Test case where BuildError is not current.")
    except RuntimeError:
        pytest.raises(BuildError, app.handle_url_build_error, error, "spam", {})

    # Test a custom handler.
    def handler(error, endpoint, values):
        # Just a test.
        return "/test_handler/"

    app.url_build_error_handlers.append(handler)
    with app.test_request_context():
        assert flask.url_for("spam") == "/test_handler/"


def test_build_error_handler_reraise(app):
    # Test a custom handler which reraises the BuildError
    def handler_raises_build_error(error, endpoint, values):
        raise error

    app.url_build_error_handlers.append(handler_raises_build_error)

    with app.test_request_context():
        pytest.raises(BuildError, flask.url_for, "not.existing")


def test_url_for_passes_special_values_to_build_error_handler(app):
    @app.url_build_error_handlers.append
    def handler(error, endpoint, values):
        assert values == {
            "_external": False,
            "_anchor": None,
            "_method": None,
            "_scheme": None,
        }
        return "handled"

    with app.test_request_context():
        flask.url_for("/")


def test_static_files(app, client):
    rv = client.get("/static/index.html")
    assert rv.status_code == 200
    assert rv.data.strip() == b"<h1>Hello World!</h1>"
    with app.test_request_context():
        assert flask.url_for("static", filename="index.html") == "/static/index.html"
    rv.close()


def test_static_url_path():
    app = flask.Flask(__name__, static_url_path="/foo")
    app.testing = True
    rv = app.test_client().get("/foo/index.html")
    assert rv.status_code == 200
    rv.close()

    with app.test_request_context():
        assert flask.url_for("static", filename="index.html") == "/foo/index.html"


def test_static_url_path_with_ending_slash():
    app = flask.Flask(__name__, static_url_path="/foo/")
    app.testing = True
    rv = app.test_client().get("/foo/index.html")
    assert rv.status_code == 200
    rv.close()

    with app.test_request_context():
        assert flask.url_for("static", filename="index.html") == "/foo/index.html"


def test_static_url_empty_path(app):
    app = flask.Flask(__name__, static_folder="", static_url_path="")
    rv = app.test_client().open("/static/index.html", method="GET")
    assert rv.status_code == 200
    rv.close()


def test_static_url_empty_path_default(app):
    app = flask.Flask(__name__, static_folder="")
    rv = app.test_client().open("/static/index.html", method="GET")
    assert rv.status_code == 200
    rv.close()


def test_static_folder_with_pathlib_path(app):
    from pathlib import Path

    app = flask.Flask(__name__, static_folder=Path("static"))
    rv = app.test_client().open("/static/index.html", method="GET")
    assert rv.status_code == 200
    rv.close()


def test_static_folder_with_ending_slash():
    app = flask.Flask(__name__, static_folder="static/")

    @app.route("/<path:path>")
    def catch_all(path):
        return path

    rv = app.test_client().get("/catch/all")
    assert rv.data == b"catch/all"


def test_static_route_with_host_matching():
    app = flask.Flask(__name__, host_matching=True, static_host="example.com")
    c = app.test_client()
    rv = c.get("http://example.com/static/index.html")
    assert rv.status_code == 200
    rv.close()
    with app.test_request_context():
        rv = flask.url_for("static", filename="index.html", _external=True)
        assert rv == "http://example.com/static/index.html"
    # Providing static_host without host_matching=True should error.
    with pytest.raises(AssertionError):
        flask.Flask(__name__, static_host="example.com")
    # Providing host_matching=True with static_folder
    # but without static_host should error.
    with pytest.raises(AssertionError):
        flask.Flask(__name__, host_matching=True)
    # Providing host_matching=True without static_host
    # but with static_folder=None should not error.
    flask.Flask(__name__, host_matching=True, static_folder=None)


def test_request_locals():
    assert repr(flask.g) == "<LocalProxy unbound>"
    assert not flask.g


def test_server_name_subdomain():
    app = flask.Flask(__name__, subdomain_matching=True)
    client = app.test_client()

    @app.route("/")
    def index():
        return "default"

    @app.route("/", subdomain="foo")
    def subdomain():
        return "subdomain"

    app.config["SERVER_NAME"] = "dev.local:5000"
    rv = client.get("/")
    assert rv.data == b"default"

    rv = client.get("/", "http://dev.local:5000")
    assert rv.data == b"default"

    rv = client.get("/", "https://dev.local:5000")
    assert rv.data == b"default"

    app.config["SERVER_NAME"] = "dev.local:443"
    rv = client.get("/", "https://dev.local")

    # Werkzeug 1.0 fixes matching https scheme with 443 port
    if rv.status_code != 404:
        assert rv.data == b"default"

    app.config["SERVER_NAME"] = "dev.local"
    rv = client.get("/", "https://dev.local")
    assert rv.data == b"default"

    # suppress Werkzeug 0.15 warning about name mismatch
    with warnings.catch_warnings():
        warnings.filterwarnings(
            "ignore", "Current server name", UserWarning, "flask.app"
        )
        rv = client.get("/", "http://foo.localhost")
        assert rv.status_code == 404

    rv = client.get("/", "http://foo.dev.local")
    assert rv.data == b"subdomain"


@pytest.mark.parametrize("key", ["TESTING", "PROPAGATE_EXCEPTIONS", "DEBUG", None])
def test_exception_propagation(app, client, key):
    app.testing = False

    @app.route("/")
    def index():
        raise ZeroDivisionError

    if key is not None:
        app.config[key] = True

        with pytest.raises(ZeroDivisionError):
            client.get("/")
    else:
        assert client.get("/").status_code == 500


@pytest.mark.parametrize("debug", [True, False])
@pytest.mark.parametrize("use_debugger", [True, False])
@pytest.mark.parametrize("use_reloader", [True, False])
@pytest.mark.parametrize("propagate_exceptions", [None, True, False])
def test_werkzeug_passthrough_errors(
    monkeypatch, debug, use_debugger, use_reloader, propagate_exceptions, app
):
    rv = {}

    # Mocks werkzeug.serving.run_simple method
    def run_simple_mock(*args, **kwargs):
        rv["passthrough_errors"] = kwargs.get("passthrough_errors")

    monkeypatch.setattr(werkzeug.serving, "run_simple", run_simple_mock)
    app.config["PROPAGATE_EXCEPTIONS"] = propagate_exceptions
    app.run(debug=debug, use_debugger=use_debugger, use_reloader=use_reloader)


def test_max_content_length(app, client):
    app.config["MAX_CONTENT_LENGTH"] = 64

    @app.before_request
    def always_first():
        flask.request.form["myfile"]
        AssertionError()

    @app.route("/accept", methods=["POST"])
    def accept_file():
        flask.request.form["myfile"]
        AssertionError()

    @app.errorhandler(413)
    def catcher(error):
        return "42"

    rv = client.post("/accept", data={"myfile": "foo" * 100})
    assert rv.data == b"42"


def test_url_processors(app, client):
    @app.url_defaults
    def add_language_code(endpoint, values):
        if flask.g.lang_code is not None and app.url_map.is_endpoint_expecting(
            endpoint, "lang_code"
        ):
            values.setdefault("lang_code", flask.g.lang_code)

    @app.url_value_preprocessor
    def pull_lang_code(endpoint, values):
        flask.g.lang_code = values.pop("lang_code", None)

    @app.route("/<lang_code>/")
    def index():
        return flask.url_for("about")

    @app.route("/<lang_code>/about")
    def about():
        return flask.url_for("something_else")

    @app.route("/foo")
    def something_else():
        return flask.url_for("about", lang_code="en")

    assert client.get("/de/").data == b"/de/about"
    assert client.get("/de/about").data == b"/foo"
    assert client.get("/foo").data == b"/en/about"


def test_inject_blueprint_url_defaults(app):
    bp = flask.Blueprint("foo", __name__, template_folder="template")

    @bp.url_defaults
    def bp_defaults(endpoint, values):
        values["page"] = "login"

    @bp.route("/<page>")
    def view(page):
        pass

    app.register_blueprint(bp)

    values = dict()
    app.inject_url_defaults("foo.view", values)
    expected = dict(page="login")
    assert values == expected

    with app.test_request_context("/somepage"):
        url = flask.url_for("foo.view")
    expected = "/login"
    assert url == expected


def test_nonascii_pathinfo(app, client):
    @app.route("/киртест")
    def index():
        return "Hello World!"

    rv = client.get("/киртест")
    assert rv.data == b"Hello World!"


def test_no_setup_after_first_request(app, client):
    app.debug = True

    @app.route("/")
    def index():
        return "Awesome"

    assert client.get("/").data == b"Awesome"

    with pytest.raises(AssertionError) as exc_info:
        app.add_url_rule("/foo", endpoint="late")

    assert "setup method 'add_url_rule'" in str(exc_info.value)


def test_routing_redirect_debugging(monkeypatch, app, client):
    app.config["DEBUG"] = True

    @app.route("/user/", methods=["GET", "POST"])
    def user():
        return flask.request.form["status"]

    # default redirect code preserves form data
    rv = client.post("/user", data={"status": "success"}, follow_redirects=True)
    assert rv.data == b"success"

    # 301 and 302 raise error
    monkeypatch.setattr(RequestRedirect, "code", 301)

    with client, pytest.raises(AssertionError) as exc_info:
        client.post("/user", data={"status": "error"}, follow_redirects=True)

    assert "canonical URL 'http://localhost/user/'" in str(exc_info.value)


def test_route_decorator_custom_endpoint(app, client):
    app.debug = True

    @app.route("/foo/")
    def foo():
        return flask.request.endpoint

    @app.route("/bar/", endpoint="bar")
    def for_bar():
        return flask.request.endpoint

    @app.route("/bar/123", endpoint="123")
    def for_bar_foo():
        return flask.request.endpoint

    with app.test_request_context():
        assert flask.url_for("foo") == "/foo/"
        assert flask.url_for("bar") == "/bar/"
        assert flask.url_for("123") == "/bar/123"

    assert client.get("/foo/").data == b"foo"
    assert client.get("/bar/").data == b"bar"
    assert client.get("/bar/123").data == b"123"


def test_get_method_on_g(app_ctx):
    assert flask.g.get("x") is None
    assert flask.g.get("x", 11) == 11
    flask.g.x = 42
    assert flask.g.get("x") == 42
    assert flask.g.x == 42


def test_g_iteration_protocol(app_ctx):
    flask.g.foo = 23
    flask.g.bar = 42
    assert "foo" in flask.g
    assert "foos" not in flask.g
    assert sorted(flask.g) == ["bar", "foo"]


def test_subdomain_basic_support():
    app = flask.Flask(__name__, subdomain_matching=True)
    app.config["SERVER_NAME"] = "localhost.localdomain"
    client = app.test_client()

    @app.route("/")
    def normal_index():
        return "normal index"

    @app.route("/", subdomain="test")
    def test_index():
        return "test index"

    rv = client.get("/", "http://localhost.localdomain/")
    assert rv.data == b"normal index"

    rv = client.get("/", "http://test.localhost.localdomain/")
    assert rv.data == b"test index"


def test_subdomain_matching():
    app = flask.Flask(__name__, subdomain_matching=True)
    client = app.test_client()
    app.config["SERVER_NAME"] = "localhost.localdomain"

    @app.route("/", subdomain="<user>")
    def index(user):
        return f"index for {user}"

    rv = client.get("/", "http://mitsuhiko.localhost.localdomain/")
    assert rv.data == b"index for mitsuhiko"


def test_subdomain_matching_with_ports():
    app = flask.Flask(__name__, subdomain_matching=True)
    app.config["SERVER_NAME"] = "localhost.localdomain:3000"
    client = app.test_client()

    @app.route("/", subdomain="<user>")
    def index(user):
        return f"index for {user}"

    rv = client.get("/", "http://mitsuhiko.localhost.localdomain:3000/")
    assert rv.data == b"index for mitsuhiko"


@pytest.mark.parametrize("matching", (False, True))
def test_subdomain_matching_other_name(matching):
    app = flask.Flask(__name__, subdomain_matching=matching)
    app.config["SERVER_NAME"] = "localhost.localdomain:3000"
    client = app.test_client()

    @app.route("/")
    def index():
        return "", 204

    # suppress Werkzeug 0.15 warning about name mismatch
    with warnings.catch_warnings():
        warnings.filterwarnings(
            "ignore", "Current server name", UserWarning, "flask.app"
        )
        # ip address can't match name
        rv = client.get("/", "http://127.0.0.1:3000/")
        assert rv.status_code == 404 if matching else 204

    # allow all subdomains if matching is disabled
    rv = client.get("/", "http://www.localhost.localdomain:3000/")
    assert rv.status_code == 404 if matching else 204


def test_multi_route_rules(app, client):
    @app.route("/")
    @app.route("/<test>/")
    def index(test="a"):
        return test

    rv = client.open("/")
    assert rv.data == b"a"
    rv = client.open("/b/")
    assert rv.data == b"b"


def test_multi_route_class_views(app, client):
    class View:
        def __init__(self, app):
            app.add_url_rule("/", "index", self.index)
            app.add_url_rule("/<test>/", "index", self.index)

        def index(self, test="a"):
            return test

    _ = View(app)
    rv = client.open("/")
    assert rv.data == b"a"
    rv = client.open("/b/")
    assert rv.data == b"b"


def test_run_defaults(monkeypatch, app):
    rv = {}

    # Mocks werkzeug.serving.run_simple method
    def run_simple_mock(*args, **kwargs):
        rv["result"] = "running..."

    monkeypatch.setattr(werkzeug.serving, "run_simple", run_simple_mock)
    app.run()
    assert rv["result"] == "running..."


def test_run_server_port(monkeypatch, app):
    rv = {}

    # Mocks werkzeug.serving.run_simple method
    def run_simple_mock(hostname, port, application, *args, **kwargs):
        rv["result"] = f"running on {hostname}:{port} ..."

    monkeypatch.setattr(werkzeug.serving, "run_simple", run_simple_mock)
    hostname, port = "localhost", 8000
    app.run(hostname, port, debug=True)
    assert rv["result"] == f"running on {hostname}:{port} ..."


@pytest.mark.parametrize(
    "host,port,server_name,expect_host,expect_port",
    (
        (None, None, "pocoo.org:8080", "pocoo.org", 8080),
        ("localhost", None, "pocoo.org:8080", "localhost", 8080),
        (None, 80, "pocoo.org:8080", "pocoo.org", 80),
        ("localhost", 80, "pocoo.org:8080", "localhost", 80),
        ("localhost", 0, "localhost:8080", "localhost", 0),
        (None, None, "localhost:8080", "localhost", 8080),
        (None, None, "localhost:0", "localhost", 0),
    ),
)
def test_run_from_config(
    monkeypatch, host, port, server_name, expect_host, expect_port, app
):
    def run_simple_mock(hostname, port, *args, **kwargs):
        assert hostname == expect_host
        assert port == expect_port

    monkeypatch.setattr(werkzeug.serving, "run_simple", run_simple_mock)
    app.config["SERVER_NAME"] = server_name
    app.run(host, port)


def test_max_cookie_size(app, client, recwarn):
    app.config["MAX_COOKIE_SIZE"] = 100

    # outside app context, default to Werkzeug static value,
    # which is also the default config
    response = flask.Response()
    default = flask.Flask.default_config["MAX_COOKIE_SIZE"]
    assert response.max_cookie_size == default

    # inside app context, use app config
    with app.app_context():
        assert flask.Response().max_cookie_size == 100

    @app.route("/")
    def index():
        r = flask.Response("", status=204)
        r.set_cookie("foo", "bar" * 100)
        return r

    client.get("/")
    assert len(recwarn) == 1
    w = recwarn.pop()
    assert "cookie is too large" in str(w.message)

    app.config["MAX_COOKIE_SIZE"] = 0

    client.get("/")
    assert len(recwarn) == 0


@require_cpython_gc
def test_app_freed_on_zero_refcount():
    # A Flask instance should not create a reference cycle that prevents CPython
    # from freeing it when all external references to it are released (see #3761).
    gc.disable()
    try:
        app = flask.Flask(__name__)
        assert app.view_functions["static"]
        weak = weakref.ref(app)
        assert weak() is not None
        del app
        assert weak() is None
    finally:
        gc.enable()


Filepath: githubCode\tests\test_blueprints.py:

import pytest
from jinja2 import TemplateNotFound
from werkzeug.http import parse_cache_control_header

import flask


def test_blueprint_specific_error_handling(app, client):
    frontend = flask.Blueprint("frontend", __name__)
    backend = flask.Blueprint("backend", __name__)
    sideend = flask.Blueprint("sideend", __name__)

    @frontend.errorhandler(403)
    def frontend_forbidden(e):
        return "frontend says no", 403

    @frontend.route("/frontend-no")
    def frontend_no():
        flask.abort(403)

    @backend.errorhandler(403)
    def backend_forbidden(e):
        return "backend says no", 403

    @backend.route("/backend-no")
    def backend_no():
        flask.abort(403)

    @sideend.route("/what-is-a-sideend")
    def sideend_no():
        flask.abort(403)

    app.register_blueprint(frontend)
    app.register_blueprint(backend)
    app.register_blueprint(sideend)

    @app.errorhandler(403)
    def app_forbidden(e):
        return "application itself says no", 403

    assert client.get("/frontend-no").data == b"frontend says no"
    assert client.get("/backend-no").data == b"backend says no"
    assert client.get("/what-is-a-sideend").data == b"application itself says no"


def test_blueprint_specific_user_error_handling(app, client):
    class MyDecoratorException(Exception):
        pass

    class MyFunctionException(Exception):
        pass

    blue = flask.Blueprint("blue", __name__)

    @blue.errorhandler(MyDecoratorException)
    def my_decorator_exception_handler(e):
        assert isinstance(e, MyDecoratorException)
        return "boom"

    def my_function_exception_handler(e):
        assert isinstance(e, MyFunctionException)
        return "bam"

    blue.register_error_handler(MyFunctionException, my_function_exception_handler)

    @blue.route("/decorator")
    def blue_deco_test():
        raise MyDecoratorException()

    @blue.route("/function")
    def blue_func_test():
        raise MyFunctionException()

    app.register_blueprint(blue)

    assert client.get("/decorator").data == b"boom"
    assert client.get("/function").data == b"bam"


def test_blueprint_app_error_handling(app, client):
    errors = flask.Blueprint("errors", __name__)

    @errors.app_errorhandler(403)
    def forbidden_handler(e):
        return "you shall not pass", 403

    @app.route("/forbidden")
    def app_forbidden():
        flask.abort(403)

    forbidden_bp = flask.Blueprint("forbidden_bp", __name__)

    @forbidden_bp.route("/nope")
    def bp_forbidden():
        flask.abort(403)

    app.register_blueprint(errors)
    app.register_blueprint(forbidden_bp)

    assert client.get("/forbidden").data == b"you shall not pass"
    assert client.get("/nope").data == b"you shall not pass"


@pytest.mark.parametrize(
    ("prefix", "rule", "url"),
    (
        ("", "/", "/"),
        ("/", "", "/"),
        ("/", "/", "/"),
        ("/foo", "", "/foo"),
        ("/foo/", "", "/foo/"),
        ("", "/bar", "/bar"),
        ("/foo/", "/bar", "/foo/bar"),
        ("/foo/", "bar", "/foo/bar"),
        ("/foo", "/bar", "/foo/bar"),
        ("/foo/", "//bar", "/foo/bar"),
        ("/foo//", "/bar", "/foo/bar"),
    ),
)
def test_blueprint_prefix_slash(app, client, prefix, rule, url):
    bp = flask.Blueprint("test", __name__, url_prefix=prefix)

    @bp.route(rule)
    def index():
        return "", 204

    app.register_blueprint(bp)
    assert client.get(url).status_code == 204


def test_blueprint_url_defaults(app, client):
    bp = flask.Blueprint("test", __name__)

    @bp.route("/foo", defaults={"baz": 42})
    def foo(bar, baz):
        return f"{bar}/{baz:d}"

    @bp.route("/bar")
    def bar(bar):
        return str(bar)

    app.register_blueprint(bp, url_prefix="/1", url_defaults={"bar": 23})
    app.register_blueprint(bp, name="test2", url_prefix="/2", url_defaults={"bar": 19})

    assert client.get("/1/foo").data == b"23/42"
    assert client.get("/2/foo").data == b"19/42"
    assert client.get("/1/bar").data == b"23"
    assert client.get("/2/bar").data == b"19"


def test_blueprint_url_processors(app, client):
    bp = flask.Blueprint("frontend", __name__, url_prefix="/<lang_code>")

    @bp.url_defaults
    def add_language_code(endpoint, values):
        values.setdefault("lang_code", flask.g.lang_code)

    @bp.url_value_preprocessor
    def pull_lang_code(endpoint, values):
        flask.g.lang_code = values.pop("lang_code")

    @bp.route("/")
    def index():
        return flask.url_for(".about")

    @bp.route("/about")
    def about():
        return flask.url_for(".index")

    app.register_blueprint(bp)

    assert client.get("/de/").data == b"/de/about"
    assert client.get("/de/about").data == b"/de/"


def test_templates_and_static(test_apps):
    from blueprintapp import app

    client = app.test_client()

    rv = client.get("/")
    assert rv.data == b"Hello from the Frontend"
    rv = client.get("/admin/")
    assert rv.data == b"Hello from the Admin"
    rv = client.get("/admin/index2")
    assert rv.data == b"Hello from the Admin"
    rv = client.get("/admin/static/test.txt")
    assert rv.data.strip() == b"Admin File"
    rv.close()
    rv = client.get("/admin/static/css/test.css")
    assert rv.data.strip() == b"/* nested file */"
    rv.close()

    # try/finally, in case other tests use this app for Blueprint tests.
    max_age_default = app.config["SEND_FILE_MAX_AGE_DEFAULT"]
    try:
        expected_max_age = 3600
        if app.config["SEND_FILE_MAX_AGE_DEFAULT"] == expected_max_age:
            expected_max_age = 7200
        app.config["SEND_FILE_MAX_AGE_DEFAULT"] = expected_max_age
        rv = client.get("/admin/static/css/test.css")
        cc = parse_cache_control_header(rv.headers["Cache-Control"])
        assert cc.max_age == expected_max_age
        rv.close()
    finally:
        app.config["SEND_FILE_MAX_AGE_DEFAULT"] = max_age_default

    with app.test_request_context():
        assert (
            flask.url_for("admin.static", filename="test.txt")
            == "/admin/static/test.txt"
        )

    with app.test_request_context():
        with pytest.raises(TemplateNotFound) as e:
            flask.render_template("missing.html")
        assert e.value.name == "missing.html"

    with flask.Flask(__name__).test_request_context():
        assert flask.render_template("nested/nested.txt") == "I'm nested"


def test_default_static_max_age(app):
    class MyBlueprint(flask.Blueprint):
        def get_send_file_max_age(self, filename):
            return 100

    blueprint = MyBlueprint("blueprint", __name__, static_folder="static")
    app.register_blueprint(blueprint)

    # try/finally, in case other tests use this app for Blueprint tests.
    max_age_default = app.config["SEND_FILE_MAX_AGE_DEFAULT"]
    try:
        with app.test_request_context():
            unexpected_max_age = 3600
            if app.config["SEND_FILE_MAX_AGE_DEFAULT"] == unexpected_max_age:
                unexpected_max_age = 7200
            app.config["SEND_FILE_MAX_AGE_DEFAULT"] = unexpected_max_age
            rv = blueprint.send_static_file("index.html")
            cc = parse_cache_control_header(rv.headers["Cache-Control"])
            assert cc.max_age == 100
            rv.close()
    finally:
        app.config["SEND_FILE_MAX_AGE_DEFAULT"] = max_age_default


def test_templates_list(test_apps):
    from blueprintapp import app

    templates = sorted(app.jinja_env.list_templates())
    assert templates == ["admin/index.html", "frontend/index.html"]


def test_dotted_name_not_allowed(app, client):
    with pytest.raises(ValueError):
        flask.Blueprint("app.ui", __name__)


def test_empty_name_not_allowed(app, client):
    with pytest.raises(ValueError):
        flask.Blueprint("", __name__)


def test_dotted_names_from_app(app, client):
    test = flask.Blueprint("test", __name__)

    @app.route("/")
    def app_index():
        return flask.url_for("test.index")

    @test.route("/test/")
    def index():
        return flask.url_for("app_index")

    app.register_blueprint(test)

    rv = client.get("/")
    assert rv.data == b"/test/"


def test_empty_url_defaults(app, client):
    bp = flask.Blueprint("bp", __name__)

    @bp.route("/", defaults={"page": 1})
    @bp.route("/page/<int:page>")
    def something(page):
        return str(page)

    app.register_blueprint(bp)

    assert client.get("/").data == b"1"
    assert client.get("/page/2").data == b"2"


def test_route_decorator_custom_endpoint(app, client):
    bp = flask.Blueprint("bp", __name__)

    @bp.route("/foo")
    def foo():
        return flask.request.endpoint

    @bp.route("/bar", endpoint="bar")
    def foo_bar():
        return flask.request.endpoint

    @bp.route("/bar/123", endpoint="123")
    def foo_bar_foo():
        return flask.request.endpoint

    @bp.route("/bar/foo")
    def bar_foo():
        return flask.request.endpoint

    app.register_blueprint(bp, url_prefix="/py")

    @app.route("/")
    def index():
        return flask.request.endpoint

    assert client.get("/").data == b"index"
    assert client.get("/py/foo").data == b"bp.foo"
    assert client.get("/py/bar").data == b"bp.bar"
    assert client.get("/py/bar/123").data == b"bp.123"
    assert client.get("/py/bar/foo").data == b"bp.bar_foo"


def test_route_decorator_custom_endpoint_with_dots(app, client):
    bp = flask.Blueprint("bp", __name__)

    with pytest.raises(ValueError):
        bp.route("/", endpoint="a.b")(lambda: "")

    with pytest.raises(ValueError):
        bp.add_url_rule("/", endpoint="a.b")

    def view():
        return ""

    view.__name__ = "a.b"

    with pytest.raises(ValueError):
        bp.add_url_rule("/", view_func=view)


def test_endpoint_decorator(app, client):
    from werkzeug.routing import Rule

    app.url_map.add(Rule("/foo", endpoint="bar"))

    bp = flask.Blueprint("bp", __name__)

    @bp.endpoint("bar")
    def foobar():
        return flask.request.endpoint

    app.register_blueprint(bp, url_prefix="/bp_prefix")

    assert client.get("/foo").data == b"bar"
    assert client.get("/bp_prefix/bar").status_code == 404


def test_template_filter(app):
    bp = flask.Blueprint("bp", __name__)

    @bp.app_template_filter()
    def my_reverse(s):
        return s[::-1]

    app.register_blueprint(bp, url_prefix="/py")
    assert "my_reverse" in app.jinja_env.filters.keys()
    assert app.jinja_env.filters["my_reverse"] == my_reverse
    assert app.jinja_env.filters["my_reverse"]("abcd") == "dcba"


def test_add_template_filter(app):
    bp = flask.Blueprint("bp", __name__)

    def my_reverse(s):
        return s[::-1]

    bp.add_app_template_filter(my_reverse)
    app.register_blueprint(bp, url_prefix="/py")
    assert "my_reverse" in app.jinja_env.filters.keys()
    assert app.jinja_env.filters["my_reverse"] == my_reverse
    assert app.jinja_env.filters["my_reverse"]("abcd") == "dcba"


def test_template_filter_with_name(app):
    bp = flask.Blueprint("bp", __name__)

    @bp.app_template_filter("strrev")
    def my_reverse(s):
        return s[::-1]

    app.register_blueprint(bp, url_prefix="/py")
    assert "strrev" in app.jinja_env.filters.keys()
    assert app.jinja_env.filters["strrev"] == my_reverse
    assert app.jinja_env.filters["strrev"]("abcd") == "dcba"


def test_add_template_filter_with_name(app):
    bp = flask.Blueprint("bp", __name__)

    def my_reverse(s):
        return s[::-1]

    bp.add_app_template_filter(my_reverse, "strrev")
    app.register_blueprint(bp, url_prefix="/py")
    assert "strrev" in app.jinja_env.filters.keys()
    assert app.jinja_env.filters["strrev"] == my_reverse
    assert app.jinja_env.filters["strrev"]("abcd") == "dcba"


def test_template_filter_with_template(app, client):
    bp = flask.Blueprint("bp", __name__)

    @bp.app_template_filter()
    def super_reverse(s):
        return s[::-1]

    app.register_blueprint(bp, url_prefix="/py")

    @app.route("/")
    def index():
        return flask.render_template("template_filter.html", value="abcd")

    rv = client.get("/")
    assert rv.data == b"dcba"


def test_template_filter_after_route_with_template(app, client):
    @app.route("/")
    def index():
        return flask.render_template("template_filter.html", value="abcd")

    bp = flask.Blueprint("bp", __name__)

    @bp.app_template_filter()
    def super_reverse(s):
        return s[::-1]

    app.register_blueprint(bp, url_prefix="/py")
    rv = client.get("/")
    assert rv.data == b"dcba"


def test_add_template_filter_with_template(app, client):
    bp = flask.Blueprint("bp", __name__)

    def super_reverse(s):
        return s[::-1]

    bp.add_app_template_filter(super_reverse)
    app.register_blueprint(bp, url_prefix="/py")

    @app.route("/")
    def index():
        return flask.render_template("template_filter.html", value="abcd")

    rv = client.get("/")
    assert rv.data == b"dcba"


def test_template_filter_with_name_and_template(app, client):
    bp = flask.Blueprint("bp", __name__)

    @bp.app_template_filter("super_reverse")
    def my_reverse(s):
        return s[::-1]

    app.register_blueprint(bp, url_prefix="/py")

    @app.route("/")
    def index():
        return flask.render_template("template_filter.html", value="abcd")

    rv = client.get("/")
    assert rv.data == b"dcba"


def test_add_template_filter_with_name_and_template(app, client):
    bp = flask.Blueprint("bp", __name__)

    def my_reverse(s):
        return s[::-1]

    bp.add_app_template_filter(my_reverse, "super_reverse")
    app.register_blueprint(bp, url_prefix="/py")

    @app.route("/")
    def index():
        return flask.render_template("template_filter.html", value="abcd")

    rv = client.get("/")
    assert rv.data == b"dcba"


def test_template_test(app):
    bp = flask.Blueprint("bp", __name__)

    @bp.app_template_test()
    def is_boolean(value):
        return isinstance(value, bool)

    app.register_blueprint(bp, url_prefix="/py")
    assert "is_boolean" in app.jinja_env.tests.keys()
    assert app.jinja_env.tests["is_boolean"] == is_boolean
    assert app.jinja_env.tests["is_boolean"](False)


def test_add_template_test(app):
    bp = flask.Blueprint("bp", __name__)

    def is_boolean(value):
        return isinstance(value, bool)

    bp.add_app_template_test(is_boolean)
    app.register_blueprint(bp, url_prefix="/py")
    assert "is_boolean" in app.jinja_env.tests.keys()
    assert app.jinja_env.tests["is_boolean"] == is_boolean
    assert app.jinja_env.tests["is_boolean"](False)


def test_template_test_with_name(app):
    bp = flask.Blueprint("bp", __name__)

    @bp.app_template_test("boolean")
    def is_boolean(value):
        return isinstance(value, bool)

    app.register_blueprint(bp, url_prefix="/py")
    assert "boolean" in app.jinja_env.tests.keys()
    assert app.jinja_env.tests["boolean"] == is_boolean
    assert app.jinja_env.tests["boolean"](False)


def test_add_template_test_with_name(app):
    bp = flask.Blueprint("bp", __name__)

    def is_boolean(value):
        return isinstance(value, bool)

    bp.add_app_template_test(is_boolean, "boolean")
    app.register_blueprint(bp, url_prefix="/py")
    assert "boolean" in app.jinja_env.tests.keys()
    assert app.jinja_env.tests["boolean"] == is_boolean
    assert app.jinja_env.tests["boolean"](False)


def test_template_test_with_template(app, client):
    bp = flask.Blueprint("bp", __name__)

    @bp.app_template_test()
    def boolean(value):
        return isinstance(value, bool)

    app.register_blueprint(bp, url_prefix="/py")

    @app.route("/")
    def index():
        return flask.render_template("template_test.html", value=False)

    rv = client.get("/")
    assert b"Success!" in rv.data


def test_template_test_after_route_with_template(app, client):
    @app.route("/")
    def index():
        return flask.render_template("template_test.html", value=False)

    bp = flask.Blueprint("bp", __name__)

    @bp.app_template_test()
    def boolean(value):
        return isinstance(value, bool)

    app.register_blueprint(bp, url_prefix="/py")
    rv = client.get("/")
    assert b"Success!" in rv.data


def test_add_template_test_with_template(app, client):
    bp = flask.Blueprint("bp", __name__)

    def boolean(value):
        return isinstance(value, bool)

    bp.add_app_template_test(boolean)
    app.register_blueprint(bp, url_prefix="/py")

    @app.route("/")
    def index():
        return flask.render_template("template_test.html", value=False)

    rv = client.get("/")
    assert b"Success!" in rv.data


def test_template_test_with_name_and_template(app, client):
    bp = flask.Blueprint("bp", __name__)

    @bp.app_template_test("boolean")
    def is_boolean(value):
        return isinstance(value, bool)

    app.register_blueprint(bp, url_prefix="/py")

    @app.route("/")
    def index():
        return flask.render_template("template_test.html", value=False)

    rv = client.get("/")
    assert b"Success!" in rv.data


def test_add_template_test_with_name_and_template(app, client):
    bp = flask.Blueprint("bp", __name__)

    def is_boolean(value):
        return isinstance(value, bool)

    bp.add_app_template_test(is_boolean, "boolean")
    app.register_blueprint(bp, url_prefix="/py")

    @app.route("/")
    def index():
        return flask.render_template("template_test.html", value=False)

    rv = client.get("/")
    assert b"Success!" in rv.data


def test_context_processing(app, client):
    answer_bp = flask.Blueprint("answer_bp", __name__)

    def template_string():
        return flask.render_template_string(
            "{% if notanswer %}{{ notanswer }} is not the answer. {% endif %}"
            "{% if answer %}{{ answer }} is the answer.{% endif %}"
        )

    # App global context processor
    @answer_bp.app_context_processor
    def not_answer_context_processor():
        return {"notanswer": 43}

    # Blueprint local context processor
    @answer_bp.context_processor
    def answer_context_processor():
        return {"answer": 42}

    # Setup endpoints for testing
    @answer_bp.route("/bp")
    def bp_page():
        return template_string()

    @app.route("/")
    def app_page():
        return template_string()

    # Register the blueprint
    app.register_blueprint(answer_bp)

    app_page_bytes = client.get("/").data
    answer_page_bytes = client.get("/bp").data

    assert b"43" in app_page_bytes
    assert b"42" not in app_page_bytes

    assert b"42" in answer_page_bytes
    assert b"43" in answer_page_bytes


def test_template_global(app):
    bp = flask.Blueprint("bp", __name__)

    @bp.app_template_global()
    def get_answer():
        return 42

    # Make sure the function is not in the jinja_env already
    assert "get_answer" not in app.jinja_env.globals.keys()
    app.register_blueprint(bp)

    # Tests
    assert "get_answer" in app.jinja_env.globals.keys()
    assert app.jinja_env.globals["get_answer"] is get_answer
    assert app.jinja_env.globals["get_answer"]() == 42

    with app.app_context():
        rv = flask.render_template_string("{{ get_answer() }}")
        assert rv == "42"


def test_request_processing(app, client):
    bp = flask.Blueprint("bp", __name__)
    evts = []

    @bp.before_request
    def before_bp():
        evts.append("before")

    @bp.after_request
    def after_bp(response):
        response.data += b"|after"
        evts.append("after")
        return response

    @bp.teardown_request
    def teardown_bp(exc):
        evts.append("teardown")

    # Setup routes for testing
    @bp.route("/bp")
    def bp_endpoint():
        return "request"

    app.register_blueprint(bp)

    assert evts == []
    rv = client.get("/bp")
    assert rv.data == b"request|after"
    assert evts == ["before", "after", "teardown"]


def test_app_request_processing(app, client):
    bp = flask.Blueprint("bp", __name__)
    evts = []

    @bp.before_app_request
    def before_app():
        evts.append("before")

    @bp.after_app_request
    def after_app(response):
        response.data += b"|after"
        evts.append("after")
        return response

    @bp.teardown_app_request
    def teardown_app(exc):
        evts.append("teardown")

    app.register_blueprint(bp)

    # Setup routes for testing
    @app.route("/")
    def bp_endpoint():
        return "request"

    # before first request
    assert evts == []

    # first request
    resp = client.get("/").data
    assert resp == b"request|after"
    assert evts == ["before", "after", "teardown"]

    # second request
    resp = client.get("/").data
    assert resp == b"request|after"
    assert evts == ["before", "after", "teardown"] * 2


def test_app_url_processors(app, client):
    bp = flask.Blueprint("bp", __name__)

    # Register app-wide url defaults and preprocessor on blueprint
    @bp.app_url_defaults
    def add_language_code(endpoint, values):
        values.setdefault("lang_code", flask.g.lang_code)

    @bp.app_url_value_preprocessor
    def pull_lang_code(endpoint, values):
        flask.g.lang_code = values.pop("lang_code")

    # Register route rules at the app level
    @app.route("/<lang_code>/")
    def index():
        return flask.url_for("about")

    @app.route("/<lang_code>/about")
    def about():
        return flask.url_for("index")

    app.register_blueprint(bp)

    assert client.get("/de/").data == b"/de/about"
    assert client.get("/de/about").data == b"/de/"


def test_nested_blueprint(app, client):
    parent = flask.Blueprint("parent", __name__)
    child = flask.Blueprint("child", __name__)
    grandchild = flask.Blueprint("grandchild", __name__)

    @parent.errorhandler(403)
    def forbidden(e):
        return "Parent no", 403

    @parent.route("/")
    def parent_index():
        return "Parent yes"

    @parent.route("/no")
    def parent_no():
        flask.abort(403)

    @child.route("/")
    def child_index():
        return "Child yes"

    @child.route("/no")
    def child_no():
        flask.abort(403)

    @grandchild.errorhandler(403)
    def grandchild_forbidden(e):
        return "Grandchild no", 403

    @grandchild.route("/")
    def grandchild_index():
        return "Grandchild yes"

    @grandchild.route("/no")
    def grandchild_no():
        flask.abort(403)

    child.register_blueprint(grandchild, url_prefix="/grandchild")
    parent.register_blueprint(child, url_prefix="/child")
    app.register_blueprint(parent, url_prefix="/parent")

    assert client.get("/parent/").data == b"Parent yes"
    assert client.get("/parent/child/").data == b"Child yes"
    assert client.get("/parent/child/grandchild/").data == b"Grandchild yes"
    assert client.get("/parent/no").data == b"Parent no"
    assert client.get("/parent/child/no").data == b"Parent no"
    assert client.get("/parent/child/grandchild/no").data == b"Grandchild no"


def test_nested_callback_order(app, client):
    parent = flask.Blueprint("parent", __name__)
    child = flask.Blueprint("child", __name__)

    @app.before_request
    def app_before1():
        flask.g.setdefault("seen", []).append("app_1")

    @app.teardown_request
    def app_teardown1(e=None):
        assert flask.g.seen.pop() == "app_1"

    @app.before_request
    def app_before2():
        flask.g.setdefault("seen", []).append("app_2")

    @app.teardown_request
    def app_teardown2(e=None):
        assert flask.g.seen.pop() == "app_2"

    @app.context_processor
    def app_ctx():
        return dict(key="app")

    @parent.before_request
    def parent_before1():
        flask.g.setdefault("seen", []).append("parent_1")

    @parent.teardown_request
    def parent_teardown1(e=None):
        assert flask.g.seen.pop() == "parent_1"

    @parent.before_request
    def parent_before2():
        flask.g.setdefault("seen", []).append("parent_2")

    @parent.teardown_request
    def parent_teardown2(e=None):
        assert flask.g.seen.pop() == "parent_2"

    @parent.context_processor
    def parent_ctx():
        return dict(key="parent")

    @child.before_request
    def child_before1():
        flask.g.setdefault("seen", []).append("child_1")

    @child.teardown_request
    def child_teardown1(e=None):
        assert flask.g.seen.pop() == "child_1"

    @child.before_request
    def child_before2():
        flask.g.setdefault("seen", []).append("child_2")

    @child.teardown_request
    def child_teardown2(e=None):
        assert flask.g.seen.pop() == "child_2"

    @child.context_processor
    def child_ctx():
        return dict(key="child")

    @child.route("/a")
    def a():
        return ", ".join(flask.g.seen)

    @child.route("/b")
    def b():
        return flask.render_template_string("{{ key }}")

    parent.register_blueprint(child)
    app.register_blueprint(parent)
    assert (
        client.get("/a").data == b"app_1, app_2, parent_1, parent_2, child_1, child_2"
    )
    assert client.get("/b").data == b"child"


@pytest.mark.parametrize(
    "parent_init, child_init, parent_registration, child_registration",
    [
        ("/parent", "/child", None, None),
        ("/parent", None, None, "/child"),
        (None, None, "/parent", "/child"),
        ("/other", "/something", "/parent", "/child"),
    ],
)
def test_nesting_url_prefixes(
    parent_init,
    child_init,
    parent_registration,
    child_registration,
    app,
    client,
) -> None:
    parent = flask.Blueprint("parent", __name__, url_prefix=parent_init)
    child = flask.Blueprint("child", __name__, url_prefix=child_init)

    @child.route("/")
    def index():
        return "index"

    parent.register_blueprint(child, url_prefix=child_registration)
    app.register_blueprint(parent, url_prefix=parent_registration)

    response = client.get("/parent/child/")
    assert response.status_code == 200


def test_nesting_subdomains(app, client) -> None:
    subdomain = "api"
    parent = flask.Blueprint("parent", __name__)
    child = flask.Blueprint("child", __name__)

    @child.route("/child/")
    def index():
        return "child"

    parent.register_blueprint(child)
    app.register_blueprint(parent, subdomain=subdomain)

    client.allow_subdomain_redirects = True

    domain_name = "domain.tld"
    app.config["SERVER_NAME"] = domain_name
    response = client.get("/child/", base_url="http://api." + domain_name)

    assert response.status_code == 200


def test_child_and_parent_subdomain(app, client) -> None:
    child_subdomain = "api"
    parent_subdomain = "parent"
    parent = flask.Blueprint("parent", __name__)
    child = flask.Blueprint("child", __name__, subdomain=child_subdomain)

    @child.route("/")
    def index():
        return "child"

    parent.register_blueprint(child)
    app.register_blueprint(parent, subdomain=parent_subdomain)

    client.allow_subdomain_redirects = True

    domain_name = "domain.tld"
    app.config["SERVER_NAME"] = domain_name
    response = client.get(
        "/", base_url=f"http://{child_subdomain}.{parent_subdomain}.{domain_name}"
    )

    assert response.status_code == 200

    response = client.get("/", base_url=f"http://{parent_subdomain}.{domain_name}")

    assert response.status_code == 404


def test_unique_blueprint_names(app, client) -> None:
    bp = flask.Blueprint("bp", __name__)
    bp2 = flask.Blueprint("bp", __name__)

    app.register_blueprint(bp)

    with pytest.raises(ValueError):
        app.register_blueprint(bp)  # same bp, same name, error

    app.register_blueprint(bp, name="again")  # same bp, different name, ok

    with pytest.raises(ValueError):
        app.register_blueprint(bp2)  # different bp, same name, error

    app.register_blueprint(bp2, name="alt")  # different bp, different name, ok


def test_self_registration(app, client) -> None:
    bp = flask.Blueprint("bp", __name__)
    with pytest.raises(ValueError):
        bp.register_blueprint(bp)


def test_blueprint_renaming(app, client) -> None:
    bp = flask.Blueprint("bp", __name__)
    bp2 = flask.Blueprint("bp2", __name__)

    @bp.get("/")
    def index():
        return flask.request.endpoint

    @bp.get("/error")
    def error():
        flask.abort(403)

    @bp.errorhandler(403)
    def forbidden(_: Exception):
        return "Error", 403

    @bp2.get("/")
    def index2():
        return flask.request.endpoint

    bp.register_blueprint(bp2, url_prefix="/a", name="sub")
    app.register_blueprint(bp, url_prefix="/a")
    app.register_blueprint(bp, url_prefix="/b", name="alt")

    assert client.get("/a/").data == b"bp.index"
    assert client.get("/b/").data == b"alt.index"
    assert client.get("/a/a/").data == b"bp.sub.index2"
    assert client.get("/b/a/").data == b"alt.sub.index2"
    assert client.get("/a/error").data == b"Error"
    assert client.get("/b/error").data == b"Error"


Filepath: githubCode\tests\test_cli.py:

# This file was part of Flask-CLI and was modified under the terms of
# its Revised BSD License. Copyright © 2015 CERN.
import importlib.metadata
import os
import platform
import ssl
import sys
import types
from functools import partial
from pathlib import Path

import click
import pytest
from _pytest.monkeypatch import notset
from click.testing import CliRunner

from flask import Blueprint
from flask import current_app
from flask import Flask
from flask.cli import AppGroup
from flask.cli import find_best_app
from flask.cli import FlaskGroup
from flask.cli import get_version
from flask.cli import load_dotenv
from flask.cli import locate_app
from flask.cli import NoAppException
from flask.cli import prepare_import
from flask.cli import run_command
from flask.cli import ScriptInfo
from flask.cli import with_appcontext

cwd = Path.cwd()
test_path = (Path(__file__) / ".." / "test_apps").resolve()


@pytest.fixture
def runner():
    return CliRunner()


def test_cli_name(test_apps):
    """Make sure the CLI object's name is the app's name and not the app itself"""
    from cliapp.app import testapp

    assert testapp.cli.name == testapp.name


def test_find_best_app(test_apps):
    class Module:
        app = Flask("appname")

    assert find_best_app(Module) == Module.app

    class Module:
        application = Flask("appname")

    assert find_best_app(Module) == Module.application

    class Module:
        myapp = Flask("appname")

    assert find_best_app(Module) == Module.myapp

    class Module:
        @staticmethod
        def create_app():
            return Flask("appname")

    app = find_best_app(Module)
    assert isinstance(app, Flask)
    assert app.name == "appname"

    class Module:
        @staticmethod
        def create_app(**kwargs):
            return Flask("appname")

    app = find_best_app(Module)
    assert isinstance(app, Flask)
    assert app.name == "appname"

    class Module:
        @staticmethod
        def make_app():
            return Flask("appname")

    app = find_best_app(Module)
    assert isinstance(app, Flask)
    assert app.name == "appname"

    class Module:
        myapp = Flask("appname1")

        @staticmethod
        def create_app():
            return Flask("appname2")

    assert find_best_app(Module) == Module.myapp

    class Module:
        myapp = Flask("appname1")

        @staticmethod
        def create_app():
            return Flask("appname2")

    assert find_best_app(Module) == Module.myapp

    class Module:
        pass

    pytest.raises(NoAppException, find_best_app, Module)

    class Module:
        myapp1 = Flask("appname1")
        myapp2 = Flask("appname2")

    pytest.raises(NoAppException, find_best_app, Module)

    class Module:
        @staticmethod
        def create_app(foo, bar):
            return Flask("appname2")

    pytest.raises(NoAppException, find_best_app, Module)

    class Module:
        @staticmethod
        def create_app():
            raise TypeError("bad bad factory!")

    pytest.raises(TypeError, find_best_app, Module)


@pytest.mark.parametrize(
    "value,path,result",
    (
        ("test", cwd, "test"),
        ("test.py", cwd, "test"),
        ("a/test", cwd / "a", "test"),
        ("test/__init__.py", cwd, "test"),
        ("test/__init__", cwd, "test"),
        # nested package
        (
            test_path / "cliapp" / "inner1" / "__init__",
            test_path,
            "cliapp.inner1",
        ),
        (
            test_path / "cliapp" / "inner1" / "inner2",
            test_path,
            "cliapp.inner1.inner2",
        ),
        # dotted name
        ("test.a.b", cwd, "test.a.b"),
        (test_path / "cliapp.app", test_path, "cliapp.app"),
        # not a Python file, will be caught during import
        (test_path / "cliapp" / "message.txt", test_path, "cliapp.message.txt"),
    ),
)
def test_prepare_import(request, value, path, result):
    """Expect the correct path to be set and the correct import and app names
    to be returned.

    :func:`prepare_exec_for_file` has a side effect where the parent directory
    of the given import is added to :data:`sys.path`. This is reset after the
    test runs.
    """
    original_path = sys.path[:]

    def reset_path():
        sys.path[:] = original_path

    request.addfinalizer(reset_path)

    assert prepare_import(value) == result
    assert sys.path[0] == str(path)


@pytest.mark.parametrize(
    "iname,aname,result",
    (
        ("cliapp.app", None, "testapp"),
        ("cliapp.app", "testapp", "testapp"),
        ("cliapp.factory", None, "app"),
        ("cliapp.factory", "create_app", "app"),
        ("cliapp.factory", "create_app()", "app"),
        ("cliapp.factory", 'create_app2("foo", "bar")', "app2_foo_bar"),
        # trailing comma space
        ("cliapp.factory", 'create_app2("foo", "bar", )', "app2_foo_bar"),
        # strip whitespace
        ("cliapp.factory", " create_app () ", "app"),
    ),
)
def test_locate_app(test_apps, iname, aname, result):
    assert locate_app(iname, aname).name == result


@pytest.mark.parametrize(
    "iname,aname",
    (
        ("notanapp.py", None),
        ("cliapp/app", None),
        ("cliapp.app", "notanapp"),
        # not enough arguments
        ("cliapp.factory", 'create_app2("foo")'),
        # invalid identifier
        ("cliapp.factory", "create_app("),
        # no app returned
        ("cliapp.factory", "no_app"),
        # nested import error
        ("cliapp.importerrorapp", None),
        # not a Python file
        ("cliapp.message.txt", None),
    ),
)
def test_locate_app_raises(test_apps, iname, aname):
    with pytest.raises(NoAppException):
        locate_app(iname, aname)


def test_locate_app_suppress_raise(test_apps):
    app = locate_app("notanapp.py", None, raise_if_not_found=False)
    assert app is None

    # only direct import error is suppressed
    with pytest.raises(NoAppException):
        locate_app("cliapp.importerrorapp", None, raise_if_not_found=False)


def test_get_version(test_apps, capsys):
    class MockCtx:
        resilient_parsing = False
        color = None

        def exit(self):
            return

    ctx = MockCtx()
    get_version(ctx, None, "test")
    out, err = capsys.readouterr()
    assert f"Python {platform.python_version()}" in out
    assert f"Flask {importlib.metadata.version('flask')}" in out
    assert f"Werkzeug {importlib.metadata.version('werkzeug')}" in out


def test_scriptinfo(test_apps, monkeypatch):
    obj = ScriptInfo(app_import_path="cliapp.app:testapp")
    app = obj.load_app()
    assert app.name == "testapp"
    assert obj.load_app() is app

    # import app with module's absolute path
    cli_app_path = str(test_path / "cliapp" / "app.py")

    obj = ScriptInfo(app_import_path=cli_app_path)
    app = obj.load_app()
    assert app.name == "testapp"
    assert obj.load_app() is app
    obj = ScriptInfo(app_import_path=f"{cli_app_path}:testapp")
    app = obj.load_app()
    assert app.name == "testapp"
    assert obj.load_app() is app

    def create_app():
        return Flask("createapp")

    obj = ScriptInfo(create_app=create_app)
    app = obj.load_app()
    assert app.name == "createapp"
    assert obj.load_app() is app

    obj = ScriptInfo()
    pytest.raises(NoAppException, obj.load_app)

    # import app from wsgi.py in current directory
    monkeypatch.chdir(test_path / "helloworld")
    obj = ScriptInfo()
    app = obj.load_app()
    assert app.name == "hello"

    # import app from app.py in current directory
    monkeypatch.chdir(test_path / "cliapp")
    obj = ScriptInfo()
    app = obj.load_app()
    assert app.name == "testapp"


def test_app_cli_has_app_context(app, runner):
    def _param_cb(ctx, param, value):
        # current_app should be available in parameter callbacks
        return bool(current_app)

    @app.cli.command()
    @click.argument("value", callback=_param_cb)
    def check(value):
        app = click.get_current_context().obj.load_app()
        # the loaded app should be the same as current_app
        same_app = current_app._get_current_object() is app
        return same_app, value

    cli = FlaskGroup(create_app=lambda: app)
    result = runner.invoke(cli, ["check", "x"], standalone_mode=False)
    assert result.return_value == (True, True)


def test_with_appcontext(runner):
    @click.command()
    @with_appcontext
    def testcmd():
        click.echo(current_app.name)

    obj = ScriptInfo(create_app=lambda: Flask("testapp"))

    result = runner.invoke(testcmd, obj=obj)
    assert result.exit_code == 0
    assert result.output == "testapp\n"


def test_appgroup_app_context(runner):
    @click.group(cls=AppGroup)
    def cli():
        pass

    @cli.command()
    def test():
        click.echo(current_app.name)

    @cli.group()
    def subgroup():
        pass

    @subgroup.command()
    def test2():
        click.echo(current_app.name)

    obj = ScriptInfo(create_app=lambda: Flask("testappgroup"))

    result = runner.invoke(cli, ["test"], obj=obj)
    assert result.exit_code == 0
    assert result.output == "testappgroup\n"

    result = runner.invoke(cli, ["subgroup", "test2"], obj=obj)
    assert result.exit_code == 0
    assert result.output == "testappgroup\n"


def test_flaskgroup_app_context(runner):
    def create_app():
        return Flask("flaskgroup")

    @click.group(cls=FlaskGroup, create_app=create_app)
    def cli(**params):
        pass

    @cli.command()
    def test():
        click.echo(current_app.name)

    result = runner.invoke(cli, ["test"])
    assert result.exit_code == 0
    assert result.output == "flaskgroup\n"


@pytest.mark.parametrize("set_debug_flag", (True, False))
def test_flaskgroup_debug(runner, set_debug_flag):
    def create_app():
        app = Flask("flaskgroup")
        app.debug = True
        return app

    @click.group(cls=FlaskGroup, create_app=create_app, set_debug_flag=set_debug_flag)
    def cli(**params):
        pass

    @cli.command()
    def test():
        click.echo(str(current_app.debug))

    result = runner.invoke(cli, ["test"])
    assert result.exit_code == 0
    assert result.output == f"{not set_debug_flag}\n"


def test_flaskgroup_nested(app, runner):
    cli = click.Group("cli")
    flask_group = FlaskGroup(name="flask", create_app=lambda: app)
    cli.add_command(flask_group)

    @flask_group.command()
    def show():
        click.echo(current_app.name)

    result = runner.invoke(cli, ["flask", "show"])
    assert result.output == "flask_test\n"


def test_no_command_echo_loading_error():
    from flask.cli import cli

    runner = CliRunner(mix_stderr=False)
    result = runner.invoke(cli, ["missing"])
    assert result.exit_code == 2
    assert "FLASK_APP" in result.stderr
    assert "Usage:" in result.stderr


def test_help_echo_loading_error():
    from flask.cli import cli

    runner = CliRunner(mix_stderr=False)
    result = runner.invoke(cli, ["--help"])
    assert result.exit_code == 0
    assert "FLASK_APP" in result.stderr
    assert "Usage:" in result.stdout


def test_help_echo_exception():
    def create_app():
        raise Exception("oh no")

    cli = FlaskGroup(create_app=create_app)
    runner = CliRunner(mix_stderr=False)
    result = runner.invoke(cli, ["--help"])
    assert result.exit_code == 0
    assert "Exception: oh no" in result.stderr
    assert "Usage:" in result.stdout


class TestRoutes:
    @pytest.fixture
    def app(self):
        app = Flask(__name__)
        app.add_url_rule(
            "/get_post/<int:x>/<int:y>",
            methods=["GET", "POST"],
            endpoint="yyy_get_post",
        )
        app.add_url_rule("/zzz_post", methods=["POST"], endpoint="aaa_post")
        return app

    @pytest.fixture
    def invoke(self, app, runner):
        cli = FlaskGroup(create_app=lambda: app)
        return partial(runner.invoke, cli)

    def expect_order(self, order, output):
        # skip the header and match the start of each row
        for expect, line in zip(order, output.splitlines()[2:]):
            # do this instead of startswith for nicer pytest output
            assert line[: len(expect)] == expect

    def test_simple(self, invoke):
        result = invoke(["routes"])
        assert result.exit_code == 0
        self.expect_order(["aaa_post", "static", "yyy_get_post"], result.output)

    def test_sort(self, app, invoke):
        default_output = invoke(["routes"]).output
        endpoint_output = invoke(["routes", "-s", "endpoint"]).output
        assert default_output == endpoint_output
        self.expect_order(
            ["static", "yyy_get_post", "aaa_post"],
            invoke(["routes", "-s", "methods"]).output,
        )
        self.expect_order(
            ["yyy_get_post", "static", "aaa_post"],
            invoke(["routes", "-s", "rule"]).output,
        )
        match_order = [r.endpoint for r in app.url_map.iter_rules()]
        self.expect_order(match_order, invoke(["routes", "-s", "match"]).output)

    def test_all_methods(self, invoke):
        output = invoke(["routes"]).output
        assert "GET, HEAD, OPTIONS, POST" not in output
        output = invoke(["routes", "--all-methods"]).output
        assert "GET, HEAD, OPTIONS, POST" in output

    def test_no_routes(self, runner):
        app = Flask(__name__, static_folder=None)
        cli = FlaskGroup(create_app=lambda: app)
        result = runner.invoke(cli, ["routes"])
        assert result.exit_code == 0
        assert "No routes were registered." in result.output

    def test_subdomain(self, runner):
        app = Flask(__name__, static_folder=None)
        app.add_url_rule("/a", subdomain="a", endpoint="a")
        app.add_url_rule("/b", subdomain="b", endpoint="b")
        cli = FlaskGroup(create_app=lambda: app)
        result = runner.invoke(cli, ["routes"])
        assert result.exit_code == 0
        assert "Subdomain" in result.output

    def test_host(self, runner):
        app = Flask(__name__, static_folder=None, host_matching=True)
        app.add_url_rule("/a", host="a", endpoint="a")
        app.add_url_rule("/b", host="b", endpoint="b")
        cli = FlaskGroup(create_app=lambda: app)
        result = runner.invoke(cli, ["routes"])
        assert result.exit_code == 0
        assert "Host" in result.output


def dotenv_not_available():
    try:
        import dotenv  # noqa: F401
    except ImportError:
        return True

    return False


need_dotenv = pytest.mark.skipif(
    dotenv_not_available(), reason="dotenv is not installed"
)


@need_dotenv
def test_load_dotenv(monkeypatch):
    # can't use monkeypatch.delitem since the keys don't exist yet
    for item in ("FOO", "BAR", "SPAM", "HAM"):
        monkeypatch._setitem.append((os.environ, item, notset))

    monkeypatch.setenv("EGGS", "3")
    monkeypatch.chdir(test_path)
    assert load_dotenv()
    assert Path.cwd() == test_path
    # .flaskenv doesn't overwrite .env
    assert os.environ["FOO"] == "env"
    # set only in .flaskenv
    assert os.environ["BAR"] == "bar"
    # set only in .env
    assert os.environ["SPAM"] == "1"
    # set manually, files don't overwrite
    assert os.environ["EGGS"] == "3"
    # test env file encoding
    assert os.environ["HAM"] == "火腿"
    # Non existent file should not load
    assert not load_dotenv("non-existent-file")


@need_dotenv
def test_dotenv_path(monkeypatch):
    for item in ("FOO", "BAR", "EGGS"):
        monkeypatch._setitem.append((os.environ, item, notset))

    load_dotenv(test_path / ".flaskenv")
    assert Path.cwd() == cwd
    assert "FOO" in os.environ


def test_dotenv_optional(monkeypatch):
    monkeypatch.setitem(sys.modules, "dotenv", None)
    monkeypatch.chdir(test_path)
    load_dotenv()
    assert "FOO" not in os.environ


@need_dotenv
def test_disable_dotenv_from_env(monkeypatch, runner):
    monkeypatch.chdir(test_path)
    monkeypatch.setitem(os.environ, "FLASK_SKIP_DOTENV", "1")
    runner.invoke(FlaskGroup())
    assert "FOO" not in os.environ


def test_run_cert_path():
    # no key
    with pytest.raises(click.BadParameter):
        run_command.make_context("run", ["--cert", __file__])

    # no cert
    with pytest.raises(click.BadParameter):
        run_command.make_context("run", ["--key", __file__])

    # cert specified first
    ctx = run_command.make_context("run", ["--cert", __file__, "--key", __file__])
    assert ctx.params["cert"] == (__file__, __file__)

    # key specified first
    ctx = run_command.make_context("run", ["--key", __file__, "--cert", __file__])
    assert ctx.params["cert"] == (__file__, __file__)


def test_run_cert_adhoc(monkeypatch):
    monkeypatch.setitem(sys.modules, "cryptography", None)

    # cryptography not installed
    with pytest.raises(click.BadParameter):
        run_command.make_context("run", ["--cert", "adhoc"])

    # cryptography installed
    monkeypatch.setitem(sys.modules, "cryptography", types.ModuleType("cryptography"))
    ctx = run_command.make_context("run", ["--cert", "adhoc"])
    assert ctx.params["cert"] == "adhoc"

    # no key with adhoc
    with pytest.raises(click.BadParameter):
        run_command.make_context("run", ["--cert", "adhoc", "--key", __file__])


def test_run_cert_import(monkeypatch):
    monkeypatch.setitem(sys.modules, "not_here", None)

    # ImportError
    with pytest.raises(click.BadParameter):
        run_command.make_context("run", ["--cert", "not_here"])

    with pytest.raises(click.BadParameter):
        run_command.make_context("run", ["--cert", "flask"])

    # SSLContext
    ssl_context = ssl.SSLContext(ssl.PROTOCOL_TLS_SERVER)

    monkeypatch.setitem(sys.modules, "ssl_context", ssl_context)
    ctx = run_command.make_context("run", ["--cert", "ssl_context"])
    assert ctx.params["cert"] is ssl_context

    # no --key with SSLContext
    with pytest.raises(click.BadParameter):
        run_command.make_context("run", ["--cert", "ssl_context", "--key", __file__])


def test_run_cert_no_ssl(monkeypatch):
    monkeypatch.setitem(sys.modules, "ssl", None)

    with pytest.raises(click.BadParameter):
        run_command.make_context("run", ["--cert", "not_here"])


def test_cli_blueprints(app):
    """Test blueprint commands register correctly to the application"""
    custom = Blueprint("custom", __name__, cli_group="customized")
    nested = Blueprint("nested", __name__)
    merged = Blueprint("merged", __name__, cli_group=None)
    late = Blueprint("late", __name__)

    @custom.cli.command("custom")
    def custom_command():
        click.echo("custom_result")

    @nested.cli.command("nested")
    def nested_command():
        click.echo("nested_result")

    @merged.cli.command("merged")
    def merged_command():
        click.echo("merged_result")

    @late.cli.command("late")
    def late_command():
        click.echo("late_result")

    app.register_blueprint(custom)
    app.register_blueprint(nested)
    app.register_blueprint(merged)
    app.register_blueprint(late, cli_group="late_registration")

    app_runner = app.test_cli_runner()

    result = app_runner.invoke(args=["customized", "custom"])
    assert "custom_result" in result.output

    result = app_runner.invoke(args=["nested", "nested"])
    assert "nested_result" in result.output

    result = app_runner.invoke(args=["merged"])
    assert "merged_result" in result.output

    result = app_runner.invoke(args=["late_registration", "late"])
    assert "late_result" in result.output


def test_cli_empty(app):
    """If a Blueprint's CLI group is empty, do not register it."""
    bp = Blueprint("blue", __name__, cli_group="blue")
    app.register_blueprint(bp)

    result = app.test_cli_runner().invoke(args=["blue", "--help"])
    assert result.exit_code == 2, f"Unexpected success:\n\n{result.output}"


def test_run_exclude_patterns():
    ctx = run_command.make_context("run", ["--exclude-patterns", __file__])
    assert ctx.params["exclude_patterns"] == [__file__]


Filepath: githubCode\tests\test_config.py:

import json
import os

import pytest

import flask

# config keys used for the TestConfig
TEST_KEY = "foo"
SECRET_KEY = "config"


def common_object_test(app):
    assert app.secret_key == "config"
    assert app.config["TEST_KEY"] == "foo"
    assert "TestConfig" not in app.config


def test_config_from_pyfile():
    app = flask.Flask(__name__)
    app.config.from_pyfile(f"{__file__.rsplit('.', 1)[0]}.py")
    common_object_test(app)


def test_config_from_object():
    app = flask.Flask(__name__)
    app.config.from_object(__name__)
    common_object_test(app)


def test_config_from_file_json():
    app = flask.Flask(__name__)
    current_dir = os.path.dirname(os.path.abspath(__file__))
    app.config.from_file(os.path.join(current_dir, "static", "config.json"), json.load)
    common_object_test(app)


def test_config_from_file_toml():
    tomllib = pytest.importorskip("tomllib", reason="tomllib added in 3.11")
    app = flask.Flask(__name__)
    current_dir = os.path.dirname(os.path.abspath(__file__))
    app.config.from_file(
        os.path.join(current_dir, "static", "config.toml"), tomllib.load, text=False
    )
    common_object_test(app)


def test_from_prefixed_env(monkeypatch):
    monkeypatch.setenv("FLASK_STRING", "value")
    monkeypatch.setenv("FLASK_BOOL", "true")
    monkeypatch.setenv("FLASK_INT", "1")
    monkeypatch.setenv("FLASK_FLOAT", "1.2")
    monkeypatch.setenv("FLASK_LIST", "[1, 2]")
    monkeypatch.setenv("FLASK_DICT", '{"k": "v"}')
    monkeypatch.setenv("NOT_FLASK_OTHER", "other")

    app = flask.Flask(__name__)
    app.config.from_prefixed_env()

    assert app.config["STRING"] == "value"
    assert app.config["BOOL"] is True
    assert app.config["INT"] == 1
    assert app.config["FLOAT"] == 1.2
    assert app.config["LIST"] == [1, 2]
    assert app.config["DICT"] == {"k": "v"}
    assert "OTHER" not in app.config


def test_from_prefixed_env_custom_prefix(monkeypatch):
    monkeypatch.setenv("FLASK_A", "a")
    monkeypatch.setenv("NOT_FLASK_A", "b")

    app = flask.Flask(__name__)
    app.config.from_prefixed_env("NOT_FLASK")

    assert app.config["A"] == "b"


def test_from_prefixed_env_nested(monkeypatch):
    monkeypatch.setenv("FLASK_EXIST__ok", "other")
    monkeypatch.setenv("FLASK_EXIST__inner__ik", "2")
    monkeypatch.setenv("FLASK_EXIST__new__more", '{"k": false}')
    monkeypatch.setenv("FLASK_NEW__K", "v")

    app = flask.Flask(__name__)
    app.config["EXIST"] = {"ok": "value", "flag": True, "inner": {"ik": 1}}
    app.config.from_prefixed_env()

    if os.name != "nt":
        assert app.config["EXIST"] == {
            "ok": "other",
            "flag": True,
            "inner": {"ik": 2},
            "new": {"more": {"k": False}},
        }
    else:
        # Windows env var keys are always uppercase.
        assert app.config["EXIST"] == {
            "ok": "value",
            "OK": "other",
            "flag": True,
            "inner": {"ik": 1},
            "INNER": {"IK": 2},
            "NEW": {"MORE": {"k": False}},
        }

    assert app.config["NEW"] == {"K": "v"}


def test_config_from_mapping():
    app = flask.Flask(__name__)
    app.config.from_mapping({"SECRET_KEY": "config", "TEST_KEY": "foo"})
    common_object_test(app)

    app = flask.Flask(__name__)
    app.config.from_mapping([("SECRET_KEY", "config"), ("TEST_KEY", "foo")])
    common_object_test(app)

    app = flask.Flask(__name__)
    app.config.from_mapping(SECRET_KEY="config", TEST_KEY="foo")
    common_object_test(app)

    app = flask.Flask(__name__)
    app.config.from_mapping(SECRET_KEY="config", TEST_KEY="foo", skip_key="skip")
    common_object_test(app)

    app = flask.Flask(__name__)
    with pytest.raises(TypeError):
        app.config.from_mapping({}, {})


def test_config_from_class():
    class Base:
        TEST_KEY = "foo"

    class Test(Base):
        SECRET_KEY = "config"

    app = flask.Flask(__name__)
    app.config.from_object(Test)
    common_object_test(app)


def test_config_from_envvar(monkeypatch):
    monkeypatch.setattr("os.environ", {})
    app = flask.Flask(__name__)

    with pytest.raises(RuntimeError) as e:
        app.config.from_envvar("FOO_SETTINGS")

    assert "'FOO_SETTINGS' is not set" in str(e.value)
    assert not app.config.from_envvar("FOO_SETTINGS", silent=True)

    monkeypatch.setattr(
        "os.environ", {"FOO_SETTINGS": f"{__file__.rsplit('.', 1)[0]}.py"}
    )
    assert app.config.from_envvar("FOO_SETTINGS")
    common_object_test(app)


def test_config_from_envvar_missing(monkeypatch):
    monkeypatch.setattr("os.environ", {"FOO_SETTINGS": "missing.cfg"})
    app = flask.Flask(__name__)
    with pytest.raises(IOError) as e:
        app.config.from_envvar("FOO_SETTINGS")
    msg = str(e.value)
    assert msg.startswith(
        "[Errno 2] Unable to load configuration file (No such file or directory):"
    )
    assert msg.endswith("missing.cfg'")
    assert not app.config.from_envvar("FOO_SETTINGS", silent=True)


def test_config_missing():
    app = flask.Flask(__name__)
    with pytest.raises(IOError) as e:
        app.config.from_pyfile("missing.cfg")
    msg = str(e.value)
    assert msg.startswith(
        "[Errno 2] Unable to load configuration file (No such file or directory):"
    )
    assert msg.endswith("missing.cfg'")
    assert not app.config.from_pyfile("missing.cfg", silent=True)


def test_config_missing_file():
    app = flask.Flask(__name__)
    with pytest.raises(IOError) as e:
        app.config.from_file("missing.json", load=json.load)
    msg = str(e.value)
    assert msg.startswith(
        "[Errno 2] Unable to load configuration file (No such file or directory):"
    )
    assert msg.endswith("missing.json'")
    assert not app.config.from_file("missing.json", load=json.load, silent=True)


def test_custom_config_class():
    class Config(flask.Config):
        pass

    class Flask(flask.Flask):
        config_class = Config

    app = Flask(__name__)
    assert isinstance(app.config, Config)
    app.config.from_object(__name__)
    common_object_test(app)


def test_session_lifetime():
    app = flask.Flask(__name__)
    app.config["PERMANENT_SESSION_LIFETIME"] = 42
    assert app.permanent_session_lifetime.seconds == 42


def test_get_namespace():
    app = flask.Flask(__name__)
    app.config["FOO_OPTION_1"] = "foo option 1"
    app.config["FOO_OPTION_2"] = "foo option 2"
    app.config["BAR_STUFF_1"] = "bar stuff 1"
    app.config["BAR_STUFF_2"] = "bar stuff 2"
    foo_options = app.config.get_namespace("FOO_")
    assert 2 == len(foo_options)
    assert "foo option 1" == foo_options["option_1"]
    assert "foo option 2" == foo_options["option_2"]
    bar_options = app.config.get_namespace("BAR_", lowercase=False)
    assert 2 == len(bar_options)
    assert "bar stuff 1" == bar_options["STUFF_1"]
    assert "bar stuff 2" == bar_options["STUFF_2"]
    foo_options = app.config.get_namespace("FOO_", trim_namespace=False)
    assert 2 == len(foo_options)
    assert "foo option 1" == foo_options["foo_option_1"]
    assert "foo option 2" == foo_options["foo_option_2"]
    bar_options = app.config.get_namespace(
        "BAR_", lowercase=False, trim_namespace=False
    )
    assert 2 == len(bar_options)
    assert "bar stuff 1" == bar_options["BAR_STUFF_1"]
    assert "bar stuff 2" == bar_options["BAR_STUFF_2"]


@pytest.mark.parametrize("encoding", ["utf-8", "iso-8859-15", "latin-1"])
def test_from_pyfile_weird_encoding(tmp_path, encoding):
    f = tmp_path / "my_config.py"
    f.write_text(f'# -*- coding: {encoding} -*-\nTEST_VALUE = "föö"\n', encoding)
    app = flask.Flask(__name__)
    app.config.from_pyfile(os.fspath(f))
    value = app.config["TEST_VALUE"]
    assert value == "föö"


Filepath: githubCode\tests\test_converters.py:

from werkzeug.routing import BaseConverter

from flask import request
from flask import session
from flask import url_for


def test_custom_converters(app, client):
    class ListConverter(BaseConverter):
        def to_python(self, value):
            return value.split(",")

        def to_url(self, value):
            base_to_url = super().to_url
            return ",".join(base_to_url(x) for x in value)

    app.url_map.converters["list"] = ListConverter

    @app.route("/<list:args>")
    def index(args):
        return "|".join(args)

    assert client.get("/1,2,3").data == b"1|2|3"

    with app.test_request_context():
        assert url_for("index", args=[4, 5, 6]) == "/4,5,6"


def test_context_available(app, client):
    class ContextConverter(BaseConverter):
        def to_python(self, value):
            assert request is not None
            assert session is not None
            return value

    app.url_map.converters["ctx"] = ContextConverter

    @app.get("/<ctx:name>")
    def index(name):
        return name

    assert client.get("/admin").data == b"admin"


Filepath: githubCode\tests\test_helpers.py:

import io
import os

import pytest
import werkzeug.exceptions

import flask
from flask.helpers import get_debug_flag


class FakePath:
    """Fake object to represent a ``PathLike object``.

    This represents a ``pathlib.Path`` object in python 3.
    See: https://www.python.org/dev/peps/pep-0519/
    """

    def __init__(self, path):
        self.path = path

    def __fspath__(self):
        return self.path


class PyBytesIO:
    def __init__(self, *args, **kwargs):
        self._io = io.BytesIO(*args, **kwargs)

    def __getattr__(self, name):
        return getattr(self._io, name)


class TestSendfile:
    def test_send_file(self, app, req_ctx):
        rv = flask.send_file("static/index.html")
        assert rv.direct_passthrough
        assert rv.mimetype == "text/html"

        with app.open_resource("static/index.html") as f:
            rv.direct_passthrough = False
            assert rv.data == f.read()

        rv.close()

    def test_static_file(self, app, req_ctx):
        # Default max_age is None.

        # Test with static file handler.
        rv = app.send_static_file("index.html")
        assert rv.cache_control.max_age is None
        rv.close()

        # Test with direct use of send_file.
        rv = flask.send_file("static/index.html")
        assert rv.cache_control.max_age is None
        rv.close()

        app.config["SEND_FILE_MAX_AGE_DEFAULT"] = 3600

        # Test with static file handler.
        rv = app.send_static_file("index.html")
        assert rv.cache_control.max_age == 3600
        rv.close()

        # Test with direct use of send_file.
        rv = flask.send_file("static/index.html")
        assert rv.cache_control.max_age == 3600
        rv.close()

        # Test with pathlib.Path.
        rv = app.send_static_file(FakePath("index.html"))
        assert rv.cache_control.max_age == 3600
        rv.close()

        class StaticFileApp(flask.Flask):
            def get_send_file_max_age(self, filename):
                return 10

        app = StaticFileApp(__name__)

        with app.test_request_context():
            # Test with static file handler.
            rv = app.send_static_file("index.html")
            assert rv.cache_control.max_age == 10
            rv.close()

            # Test with direct use of send_file.
            rv = flask.send_file("static/index.html")
            assert rv.cache_control.max_age == 10
            rv.close()

    def test_send_from_directory(self, app, req_ctx):
        app.root_path = os.path.join(
            os.path.dirname(__file__), "test_apps", "subdomaintestmodule"
        )
        rv = flask.send_from_directory("static", "hello.txt")
        rv.direct_passthrough = False
        assert rv.data.strip() == b"Hello Subdomain"
        rv.close()


class TestUrlFor:
    def test_url_for_with_anchor(self, app, req_ctx):
        @app.route("/")
        def index():
            return "42"

        assert flask.url_for("index", _anchor="x y") == "/#x%20y"

    def test_url_for_with_scheme(self, app, req_ctx):
        @app.route("/")
        def index():
            return "42"

        assert (
            flask.url_for("index", _external=True, _scheme="https")
            == "https://localhost/"
        )

    def test_url_for_with_scheme_not_external(self, app, req_ctx):
        app.add_url_rule("/", endpoint="index")

        # Implicit external with scheme.
        url = flask.url_for("index", _scheme="https")
        assert url == "https://localhost/"

        # Error when external=False with scheme
        with pytest.raises(ValueError):
            flask.url_for("index", _scheme="https", _external=False)

    def test_url_for_with_alternating_schemes(self, app, req_ctx):
        @app.route("/")
        def index():
            return "42"

        assert flask.url_for("index", _external=True) == "http://localhost/"
        assert (
            flask.url_for("index", _external=True, _scheme="https")
            == "https://localhost/"
        )
        assert flask.url_for("index", _external=True) == "http://localhost/"

    def test_url_with_method(self, app, req_ctx):
        from flask.views import MethodView

        class MyView(MethodView):
            def get(self, id=None):
                if id is None:
                    return "List"
                return f"Get {id:d}"

            def post(self):
                return "Create"

        myview = MyView.as_view("myview")
        app.add_url_rule("/myview/", methods=["GET"], view_func=myview)
        app.add_url_rule("/myview/<int:id>", methods=["GET"], view_func=myview)
        app.add_url_rule("/myview/create", methods=["POST"], view_func=myview)

        assert flask.url_for("myview", _method="GET") == "/myview/"
        assert flask.url_for("myview", id=42, _method="GET") == "/myview/42"
        assert flask.url_for("myview", _method="POST") == "/myview/create"

    def test_url_for_with_self(self, app, req_ctx):
        @app.route("/<self>")
        def index(self):
            return "42"

        assert flask.url_for("index", self="2") == "/2"


def test_redirect_no_app():
    response = flask.redirect("https://localhost", 307)
    assert response.location == "https://localhost"
    assert response.status_code == 307


def test_redirect_with_app(app):
    def redirect(location, code=302):
        raise ValueError

    app.redirect = redirect

    with app.app_context(), pytest.raises(ValueError):
        flask.redirect("other")


def test_abort_no_app():
    with pytest.raises(werkzeug.exceptions.Unauthorized):
        flask.abort(401)

    with pytest.raises(LookupError):
        flask.abort(900)


def test_app_aborter_class():
    class MyAborter(werkzeug.exceptions.Aborter):
        pass

    class MyFlask(flask.Flask):
        aborter_class = MyAborter

    app = MyFlask(__name__)
    assert isinstance(app.aborter, MyAborter)


def test_abort_with_app(app):
    class My900Error(werkzeug.exceptions.HTTPException):
        code = 900

    app.aborter.mapping[900] = My900Error

    with app.app_context(), pytest.raises(My900Error):
        flask.abort(900)


class TestNoImports:
    """Test Flasks are created without import.

    Avoiding ``__import__`` helps create Flask instances where there are errors
    at import time.  Those runtime errors will be apparent to the user soon
    enough, but tools which build Flask instances meta-programmatically benefit
    from a Flask which does not ``__import__``.  Instead of importing to
    retrieve file paths or metadata on a module or package, use the pkgutil and
    imp modules in the Python standard library.
    """

    def test_name_with_import_error(self, modules_tmp_path):
        (modules_tmp_path / "importerror.py").write_text("raise NotImplementedError()")
        try:
            flask.Flask("importerror")
        except NotImplementedError:
            AssertionError("Flask(import_name) is importing import_name.")


class TestStreaming:
    def test_streaming_with_context(self, app, client):
        @app.route("/")
        def index():
            def generate():
                yield "Hello "
                yield flask.request.args["name"]
                yield "!"

            return flask.Response(flask.stream_with_context(generate()))

        rv = client.get("/?name=World")
        assert rv.data == b"Hello World!"

    def test_streaming_with_context_as_decorator(self, app, client):
        @app.route("/")
        def index():
            @flask.stream_with_context
            def generate(hello):
                yield hello
                yield flask.request.args["name"]
                yield "!"

            return flask.Response(generate("Hello "))

        rv = client.get("/?name=World")
        assert rv.data == b"Hello World!"

    def test_streaming_with_context_and_custom_close(self, app, client):
        called = []

        class Wrapper:
            def __init__(self, gen):
                self._gen = gen

            def __iter__(self):
                return self

            def close(self):
                called.append(42)

            def __next__(self):
                return next(self._gen)

            next = __next__

        @app.route("/")
        def index():
            def generate():
                yield "Hello "
                yield flask.request.args["name"]
                yield "!"

            return flask.Response(flask.stream_with_context(Wrapper(generate())))

        rv = client.get("/?name=World")
        assert rv.data == b"Hello World!"
        assert called == [42]

    def test_stream_keeps_session(self, app, client):
        @app.route("/")
        def index():
            flask.session["test"] = "flask"

            @flask.stream_with_context
            def gen():
                yield flask.session["test"]

            return flask.Response(gen())

        rv = client.get("/")
        assert rv.data == b"flask"


class TestHelpers:
    @pytest.mark.parametrize(
        ("debug", "expect"),
        [
            ("", False),
            ("0", False),
            ("False", False),
            ("No", False),
            ("True", True),
        ],
    )
    def test_get_debug_flag(self, monkeypatch, debug, expect):
        monkeypatch.setenv("FLASK_DEBUG", debug)
        assert get_debug_flag() == expect

    def test_make_response(self):
        app = flask.Flask(__name__)
        with app.test_request_context():
            rv = flask.helpers.make_response()
            assert rv.status_code == 200
            assert rv.mimetype == "text/html"

            rv = flask.helpers.make_response("Hello")
            assert rv.status_code == 200
            assert rv.data == b"Hello"
            assert rv.mimetype == "text/html"

    @pytest.mark.parametrize("mode", ("r", "rb", "rt"))
    def test_open_resource(self, mode):
        app = flask.Flask(__name__)

        with app.open_resource("static/index.html", mode) as f:
            assert "<h1>Hello World!</h1>" in str(f.read())

    @pytest.mark.parametrize("mode", ("w", "x", "a", "r+"))
    def test_open_resource_exceptions(self, mode):
        app = flask.Flask(__name__)

        with pytest.raises(ValueError):
            app.open_resource("static/index.html", mode)


Filepath: githubCode\tests\test_instance_config.py:

import os

import pytest

import flask


def test_explicit_instance_paths(modules_tmp_path):
    with pytest.raises(ValueError, match=".*must be absolute"):
        flask.Flask(__name__, instance_path="instance")

    app = flask.Flask(__name__, instance_path=os.fspath(modules_tmp_path))
    assert app.instance_path == os.fspath(modules_tmp_path)


def test_uninstalled_module_paths(modules_tmp_path, purge_module):
    (modules_tmp_path / "config_module_app.py").write_text(
        "import os\n"
        "import flask\n"
        "here = os.path.abspath(os.path.dirname(__file__))\n"
        "app = flask.Flask(__name__)\n"
    )
    purge_module("config_module_app")

    from config_module_app import app

    assert app.instance_path == os.fspath(modules_tmp_path / "instance")


def test_uninstalled_package_paths(modules_tmp_path, purge_module):
    app = modules_tmp_path / "config_package_app"
    app.mkdir()
    (app / "__init__.py").write_text(
        "import os\n"
        "import flask\n"
        "here = os.path.abspath(os.path.dirname(__file__))\n"
        "app = flask.Flask(__name__)\n"
    )
    purge_module("config_package_app")

    from config_package_app import app

    assert app.instance_path == os.fspath(modules_tmp_path / "instance")


def test_uninstalled_namespace_paths(tmp_path, monkeypatch, purge_module):
    def create_namespace(package):
        project = tmp_path / f"project-{package}"
        monkeypatch.syspath_prepend(os.fspath(project))
        ns = project / "namespace" / package
        ns.mkdir(parents=True)
        (ns / "__init__.py").write_text("import flask\napp = flask.Flask(__name__)\n")
        return project

    _ = create_namespace("package1")
    project2 = create_namespace("package2")
    purge_module("namespace.package2")
    purge_module("namespace")

    from namespace.package2 import app

    assert app.instance_path == os.fspath(project2 / "instance")


def test_installed_module_paths(
    modules_tmp_path, modules_tmp_path_prefix, purge_module, site_packages, limit_loader
):
    (site_packages / "site_app.py").write_text(
        "import flask\napp = flask.Flask(__name__)\n"
    )
    purge_module("site_app")

    from site_app import app

    assert app.instance_path == os.fspath(
        modules_tmp_path / "var" / "site_app-instance"
    )


def test_installed_package_paths(
    limit_loader, modules_tmp_path, modules_tmp_path_prefix, purge_module, monkeypatch
):
    installed_path = modules_tmp_path / "path"
    installed_path.mkdir()
    monkeypatch.syspath_prepend(installed_path)

    app = installed_path / "installed_package"
    app.mkdir()
    (app / "__init__.py").write_text("import flask\napp = flask.Flask(__name__)\n")
    purge_module("installed_package")

    from installed_package import app

    assert app.instance_path == os.fspath(
        modules_tmp_path / "var" / "installed_package-instance"
    )


def test_prefix_package_paths(
    limit_loader, modules_tmp_path, modules_tmp_path_prefix, purge_module, site_packages
):
    app = site_packages / "site_package"
    app.mkdir()
    (app / "__init__.py").write_text("import flask\napp = flask.Flask(__name__)\n")
    purge_module("site_package")

    import site_package

    assert site_package.app.instance_path == os.fspath(
        modules_tmp_path / "var" / "site_package-instance"
    )


Filepath: githubCode\tests\test_json.py:

import datetime
import decimal
import io
import uuid

import pytest
from werkzeug.http import http_date

import flask
from flask import json
from flask.json.provider import DefaultJSONProvider


@pytest.mark.parametrize("debug", (True, False))
def test_bad_request_debug_message(app, client, debug):
    app.config["DEBUG"] = debug
    app.config["TRAP_BAD_REQUEST_ERRORS"] = False

    @app.route("/json", methods=["POST"])
    def post_json():
        flask.request.get_json()
        return None

    rv = client.post("/json", data=None, content_type="application/json")
    assert rv.status_code == 400
    contains = b"Failed to decode JSON object" in rv.data
    assert contains == debug


def test_json_bad_requests(app, client):
    @app.route("/json", methods=["POST"])
    def return_json():
        return flask.jsonify(foo=str(flask.request.get_json()))

    rv = client.post("/json", data="malformed", content_type="application/json")
    assert rv.status_code == 400


def test_json_custom_mimetypes(app, client):
    @app.route("/json", methods=["POST"])
    def return_json():
        return flask.request.get_json()

    rv = client.post("/json", data='"foo"', content_type="application/x+json")
    assert rv.data == b"foo"


@pytest.mark.parametrize(
    "test_value,expected", [(True, '"\\u2603"'), (False, '"\u2603"')]
)
def test_json_as_unicode(test_value, expected, app, app_ctx):
    app.json.ensure_ascii = test_value
    rv = app.json.dumps("\N{SNOWMAN}")
    assert rv == expected


def test_json_dump_to_file(app, app_ctx):
    test_data = {"name": "Flask"}
    out = io.StringIO()

    flask.json.dump(test_data, out)
    out.seek(0)
    rv = flask.json.load(out)
    assert rv == test_data


@pytest.mark.parametrize(
    "test_value", [0, -1, 1, 23, 3.14, "s", "longer string", True, False, None]
)
def test_jsonify_basic_types(test_value, app, client):
    url = "/jsonify_basic_types"
    app.add_url_rule(url, url, lambda x=test_value: flask.jsonify(x))
    rv = client.get(url)
    assert rv.mimetype == "application/json"
    assert flask.json.loads(rv.data) == test_value


def test_jsonify_dicts(app, client):
    d = {
        "a": 0,
        "b": 23,
        "c": 3.14,
        "d": "t",
        "e": "Hi",
        "f": True,
        "g": False,
        "h": ["test list", 10, False],
        "i": {"test": "dict"},
    }

    @app.route("/kw")
    def return_kwargs():
        return flask.jsonify(**d)

    @app.route("/dict")
    def return_dict():
        return flask.jsonify(d)

    for url in "/kw", "/dict":
        rv = client.get(url)
        assert rv.mimetype == "application/json"
        assert flask.json.loads(rv.data) == d


def test_jsonify_arrays(app, client):
    """Test jsonify of lists and args unpacking."""
    a_list = [
        0,
        42,
        3.14,
        "t",
        "hello",
        True,
        False,
        ["test list", 2, False],
        {"test": "dict"},
    ]

    @app.route("/args_unpack")
    def return_args_unpack():
        return flask.jsonify(*a_list)

    @app.route("/array")
    def return_array():
        return flask.jsonify(a_list)

    for url in "/args_unpack", "/array":
        rv = client.get(url)
        assert rv.mimetype == "application/json"
        assert flask.json.loads(rv.data) == a_list


@pytest.mark.parametrize(
    "value", [datetime.datetime(1973, 3, 11, 6, 30, 45), datetime.date(1975, 1, 5)]
)
def test_jsonify_datetime(app, client, value):
    @app.route("/")
    def index():
        return flask.jsonify(value=value)

    r = client.get()
    assert r.json["value"] == http_date(value)


class FixedOffset(datetime.tzinfo):
    """Fixed offset in hours east from UTC.

    This is a slight adaptation of the ``FixedOffset`` example found in
    https://docs.python.org/2.7/library/datetime.html.
    """

    def __init__(self, hours, name):
        self.__offset = datetime.timedelta(hours=hours)
        self.__name = name

    def utcoffset(self, dt):
        return self.__offset

    def tzname(self, dt):
        return self.__name

    def dst(self, dt):
        return datetime.timedelta()


@pytest.mark.parametrize("tz", (("UTC", 0), ("PST", -8), ("KST", 9)))
def test_jsonify_aware_datetimes(tz):
    """Test if aware datetime.datetime objects are converted into GMT."""
    tzinfo = FixedOffset(hours=tz[1], name=tz[0])
    dt = datetime.datetime(2017, 1, 1, 12, 34, 56, tzinfo=tzinfo)
    gmt = FixedOffset(hours=0, name="GMT")
    expected = dt.astimezone(gmt).strftime('"%a, %d %b %Y %H:%M:%S %Z"')
    assert flask.json.dumps(dt) == expected


def test_jsonify_uuid_types(app, client):
    """Test jsonify with uuid.UUID types"""

    test_uuid = uuid.UUID(bytes=b"\xDE\xAD\xBE\xEF" * 4)
    url = "/uuid_test"
    app.add_url_rule(url, url, lambda: flask.jsonify(x=test_uuid))

    rv = client.get(url)

    rv_x = flask.json.loads(rv.data)["x"]
    assert rv_x == str(test_uuid)
    rv_uuid = uuid.UUID(rv_x)
    assert rv_uuid == test_uuid


def test_json_decimal():
    rv = flask.json.dumps(decimal.Decimal("0.003"))
    assert rv == '"0.003"'


def test_json_attr(app, client):
    @app.route("/add", methods=["POST"])
    def add():
        json = flask.request.get_json()
        return str(json["a"] + json["b"])

    rv = client.post(
        "/add",
        data=flask.json.dumps({"a": 1, "b": 2}),
        content_type="application/json",
    )
    assert rv.data == b"3"


def test_tojson_filter(app, req_ctx):
    # The tojson filter is tested in Jinja, this confirms that it's
    # using Flask's dumps.
    rv = flask.render_template_string(
        "const data = {{ data|tojson }};",
        data={"name": "</script>", "time": datetime.datetime(2021, 2, 1, 7, 15)},
    )
    assert rv == (
        'const data = {"name": "\\u003c/script\\u003e",'
        ' "time": "Mon, 01 Feb 2021 07:15:00 GMT"};'
    )


def test_json_customization(app, client):
    class X:  # noqa: B903, for Python2 compatibility
        def __init__(self, val):
            self.val = val

    def default(o):
        if isinstance(o, X):
            return f"<{o.val}>"

        return DefaultJSONProvider.default(o)

    class CustomProvider(DefaultJSONProvider):
        def object_hook(self, obj):
            if len(obj) == 1 and "_foo" in obj:
                return X(obj["_foo"])

            return obj

        def loads(self, s, **kwargs):
            kwargs.setdefault("object_hook", self.object_hook)
            return super().loads(s, **kwargs)

    app.json = CustomProvider(app)
    app.json.default = default

    @app.route("/", methods=["POST"])
    def index():
        return flask.json.dumps(flask.request.get_json()["x"])

    rv = client.post(
        "/",
        data=flask.json.dumps({"x": {"_foo": 42}}),
        content_type="application/json",
    )
    assert rv.data == b'"<42>"'


def _has_encoding(name):
    try:
        import codecs

        codecs.lookup(name)
        return True
    except LookupError:
        return False


def test_json_key_sorting(app, client):
    app.debug = True
    assert app.json.sort_keys
    d = dict.fromkeys(range(20), "foo")

    @app.route("/")
    def index():
        return flask.jsonify(values=d)

    rv = client.get("/")
    lines = [x.strip() for x in rv.data.strip().decode("utf-8").splitlines()]
    sorted_by_str = [
        "{",
        '"values": {',
        '"0": "foo",',
        '"1": "foo",',
        '"10": "foo",',
        '"11": "foo",',
        '"12": "foo",',
        '"13": "foo",',
        '"14": "foo",',
        '"15": "foo",',
        '"16": "foo",',
        '"17": "foo",',
        '"18": "foo",',
        '"19": "foo",',
        '"2": "foo",',
        '"3": "foo",',
        '"4": "foo",',
        '"5": "foo",',
        '"6": "foo",',
        '"7": "foo",',
        '"8": "foo",',
        '"9": "foo"',
        "}",
        "}",
    ]
    sorted_by_int = [
        "{",
        '"values": {',
        '"0": "foo",',
        '"1": "foo",',
        '"2": "foo",',
        '"3": "foo",',
        '"4": "foo",',
        '"5": "foo",',
        '"6": "foo",',
        '"7": "foo",',
        '"8": "foo",',
        '"9": "foo",',
        '"10": "foo",',
        '"11": "foo",',
        '"12": "foo",',
        '"13": "foo",',
        '"14": "foo",',
        '"15": "foo",',
        '"16": "foo",',
        '"17": "foo",',
        '"18": "foo",',
        '"19": "foo"',
        "}",
        "}",
    ]

    try:
        assert lines == sorted_by_int
    except AssertionError:
        assert lines == sorted_by_str


def test_html_method():
    class ObjectWithHTML:
        def __html__(self):
            return "<p>test</p>"

    result = json.dumps(ObjectWithHTML())
    assert result == '"<p>test</p>"'


Filepath: githubCode\tests\test_json_tag.py:

from datetime import datetime
from datetime import timezone
from uuid import uuid4

import pytest
from markupsafe import Markup

from flask.json.tag import JSONTag
from flask.json.tag import TaggedJSONSerializer


@pytest.mark.parametrize(
    "data",
    (
        {" t": (1, 2, 3)},
        {" t__": b"a"},
        {" di": " di"},
        {"x": (1, 2, 3), "y": 4},
        (1, 2, 3),
        [(1, 2, 3)],
        b"\xff",
        Markup("<html>"),
        uuid4(),
        datetime.now(tz=timezone.utc).replace(microsecond=0),
    ),
)
def test_dump_load_unchanged(data):
    s = TaggedJSONSerializer()
    assert s.loads(s.dumps(data)) == data


def test_duplicate_tag():
    class TagDict(JSONTag):
        key = " d"

    s = TaggedJSONSerializer()
    pytest.raises(KeyError, s.register, TagDict)
    s.register(TagDict, force=True, index=0)
    assert isinstance(s.tags[" d"], TagDict)
    assert isinstance(s.order[0], TagDict)


def test_custom_tag():
    class Foo:  # noqa: B903, for Python2 compatibility
        def __init__(self, data):
            self.data = data

    class TagFoo(JSONTag):
        __slots__ = ()
        key = " f"

        def check(self, value):
            return isinstance(value, Foo)

        def to_json(self, value):
            return self.serializer.tag(value.data)

        def to_python(self, value):
            return Foo(value)

    s = TaggedJSONSerializer()
    s.register(TagFoo)
    assert s.loads(s.dumps(Foo("bar"))).data == "bar"


def test_tag_interface():
    t = JSONTag(None)
    pytest.raises(NotImplementedError, t.check, None)
    pytest.raises(NotImplementedError, t.to_json, None)
    pytest.raises(NotImplementedError, t.to_python, None)


def test_tag_order():
    class Tag1(JSONTag):
        key = " 1"

    class Tag2(JSONTag):
        key = " 2"

    s = TaggedJSONSerializer()

    s.register(Tag1, index=-1)
    assert isinstance(s.order[-2], Tag1)

    s.register(Tag2, index=None)
    assert isinstance(s.order[-1], Tag2)


Filepath: githubCode\tests\test_logging.py:

import logging
import sys
from io import StringIO

import pytest

from flask.logging import default_handler
from flask.logging import has_level_handler
from flask.logging import wsgi_errors_stream


@pytest.fixture(autouse=True)
def reset_logging(pytestconfig):
    root_handlers = logging.root.handlers[:]
    logging.root.handlers = []
    root_level = logging.root.level

    logger = logging.getLogger("flask_test")
    logger.handlers = []
    logger.setLevel(logging.NOTSET)

    logging_plugin = pytestconfig.pluginmanager.unregister(name="logging-plugin")

    yield

    logging.root.handlers[:] = root_handlers
    logging.root.setLevel(root_level)

    logger.handlers = []
    logger.setLevel(logging.NOTSET)

    if logging_plugin:
        pytestconfig.pluginmanager.register(logging_plugin, "logging-plugin")


def test_logger(app):
    assert app.logger.name == "flask_test"
    assert app.logger.level == logging.NOTSET
    assert app.logger.handlers == [default_handler]


def test_logger_debug(app):
    app.debug = True
    assert app.logger.level == logging.DEBUG
    assert app.logger.handlers == [default_handler]


def test_existing_handler(app):
    logging.root.addHandler(logging.StreamHandler())
    assert app.logger.level == logging.NOTSET
    assert not app.logger.handlers


def test_wsgi_errors_stream(app, client):
    @app.route("/")
    def index():
        app.logger.error("test")
        return ""

    stream = StringIO()
    client.get("/", errors_stream=stream)
    assert "ERROR in test_logging: test" in stream.getvalue()

    assert wsgi_errors_stream._get_current_object() is sys.stderr

    with app.test_request_context(errors_stream=stream):
        assert wsgi_errors_stream._get_current_object() is stream


def test_has_level_handler():
    logger = logging.getLogger("flask.app")
    assert not has_level_handler(logger)

    handler = logging.StreamHandler()
    logging.root.addHandler(handler)
    assert has_level_handler(logger)

    logger.propagate = False
    assert not has_level_handler(logger)
    logger.propagate = True

    handler.setLevel(logging.ERROR)
    assert not has_level_handler(logger)


def test_log_view_exception(app, client):
    @app.route("/")
    def index():
        raise Exception("test")

    app.testing = False
    stream = StringIO()
    rv = client.get("/", errors_stream=stream)
    assert rv.status_code == 500
    assert rv.data
    err = stream.getvalue()
    assert "Exception on / [GET]" in err
    assert "Exception: test" in err


Filepath: githubCode\tests\test_regression.py:

import flask


def test_aborting(app):
    class Foo(Exception):
        whatever = 42

    @app.errorhandler(Foo)
    def handle_foo(e):
        return str(e.whatever)

    @app.route("/")
    def index():
        raise flask.abort(flask.redirect(flask.url_for("test")))

    @app.route("/test")
    def test():
        raise Foo()

    with app.test_client() as c:
        rv = c.get("/")
        location_parts = rv.headers["Location"].rpartition("/")

        if location_parts[0]:
            # For older Werkzeug that used absolute redirects.
            assert location_parts[0] == "http://localhost"

        assert location_parts[2] == "test"
        rv = c.get("/test")
        assert rv.data == b"42"


Filepath: githubCode\tests\test_reqctx.py:

import warnings

import pytest

import flask
from flask.globals import request_ctx
from flask.sessions import SecureCookieSessionInterface
from flask.sessions import SessionInterface

try:
    from greenlet import greenlet
except ImportError:
    greenlet = None


def test_teardown_on_pop(app):
    buffer = []

    @app.teardown_request
    def end_of_request(exception):
        buffer.append(exception)

    ctx = app.test_request_context()
    ctx.push()
    assert buffer == []
    ctx.pop()
    assert buffer == [None]


def test_teardown_with_previous_exception(app):
    buffer = []

    @app.teardown_request
    def end_of_request(exception):
        buffer.append(exception)

    try:
        raise Exception("dummy")
    except Exception:
        pass

    with app.test_request_context():
        assert buffer == []
    assert buffer == [None]


def test_teardown_with_handled_exception(app):
    buffer = []

    @app.teardown_request
    def end_of_request(exception):
        buffer.append(exception)

    with app.test_request_context():
        assert buffer == []
        try:
            raise Exception("dummy")
        except Exception:
            pass
    assert buffer == [None]


def test_proper_test_request_context(app):
    app.config.update(SERVER_NAME="localhost.localdomain:5000")

    @app.route("/")
    def index():
        return None

    @app.route("/", subdomain="foo")
    def sub():
        return None

    with app.test_request_context("/"):
        assert (
            flask.url_for("index", _external=True)
            == "http://localhost.localdomain:5000/"
        )

    with app.test_request_context("/"):
        assert (
            flask.url_for("sub", _external=True)
            == "http://foo.localhost.localdomain:5000/"
        )

    # suppress Werkzeug 0.15 warning about name mismatch
    with warnings.catch_warnings():
        warnings.filterwarnings(
            "ignore", "Current server name", UserWarning, "flask.app"
        )
        with app.test_request_context(
            "/", environ_overrides={"HTTP_HOST": "localhost"}
        ):
            pass

    app.config.update(SERVER_NAME="localhost")
    with app.test_request_context("/", environ_overrides={"SERVER_NAME": "localhost"}):
        pass

    app.config.update(SERVER_NAME="localhost:80")
    with app.test_request_context(
        "/", environ_overrides={"SERVER_NAME": "localhost:80"}
    ):
        pass


def test_context_binding(app):
    @app.route("/")
    def index():
        return f"Hello {flask.request.args['name']}!"

    @app.route("/meh")
    def meh():
        return flask.request.url

    with app.test_request_context("/?name=World"):
        assert index() == "Hello World!"
    with app.test_request_context("/meh"):
        assert meh() == "http://localhost/meh"
    assert not flask.request


def test_context_test(app):
    assert not flask.request
    assert not flask.has_request_context()
    ctx = app.test_request_context()
    ctx.push()
    try:
        assert flask.request
        assert flask.has_request_context()
    finally:
        ctx.pop()


def test_manual_context_binding(app):
    @app.route("/")
    def index():
        return f"Hello {flask.request.args['name']}!"

    ctx = app.test_request_context("/?name=World")
    ctx.push()
    assert index() == "Hello World!"
    ctx.pop()
    with pytest.raises(RuntimeError):
        index()


@pytest.mark.skipif(greenlet is None, reason="greenlet not installed")
class TestGreenletContextCopying:
    def test_greenlet_context_copying(self, app, client):
        greenlets = []

        @app.route("/")
        def index():
            flask.session["fizz"] = "buzz"
            reqctx = request_ctx.copy()

            def g():
                assert not flask.request
                assert not flask.current_app
                with reqctx:
                    assert flask.request
                    assert flask.current_app == app
                    assert flask.request.path == "/"
                    assert flask.request.args["foo"] == "bar"
                    assert flask.session.get("fizz") == "buzz"
                assert not flask.request
                return 42

            greenlets.append(greenlet(g))
            return "Hello World!"

        rv = client.get("/?foo=bar")
        assert rv.data == b"Hello World!"

        result = greenlets[0].run()
        assert result == 42

    def test_greenlet_context_copying_api(self, app, client):
        greenlets = []

        @app.route("/")
        def index():
            flask.session["fizz"] = "buzz"

            @flask.copy_current_request_context
            def g():
                assert flask.request
                assert flask.current_app == app
                assert flask.request.path == "/"
                assert flask.request.args["foo"] == "bar"
                assert flask.session.get("fizz") == "buzz"
                return 42

            greenlets.append(greenlet(g))
            return "Hello World!"

        rv = client.get("/?foo=bar")
        assert rv.data == b"Hello World!"

        result = greenlets[0].run()
        assert result == 42


def test_session_error_pops_context():
    class SessionError(Exception):
        pass

    class FailingSessionInterface(SessionInterface):
        def open_session(self, app, request):
            raise SessionError()

    class CustomFlask(flask.Flask):
        session_interface = FailingSessionInterface()

    app = CustomFlask(__name__)

    @app.route("/")
    def index():
        # shouldn't get here
        AssertionError()

    response = app.test_client().get("/")
    assert response.status_code == 500
    assert not flask.request
    assert not flask.current_app


def test_session_dynamic_cookie_name():
    # This session interface will use a cookie with a different name if the
    # requested url ends with the string "dynamic_cookie"
    class PathAwareSessionInterface(SecureCookieSessionInterface):
        def get_cookie_name(self, app):
            if flask.request.url.endswith("dynamic_cookie"):
                return "dynamic_cookie_name"
            else:
                return super().get_cookie_name(app)

    class CustomFlask(flask.Flask):
        session_interface = PathAwareSessionInterface()

    app = CustomFlask(__name__)
    app.secret_key = "secret_key"

    @app.route("/set", methods=["POST"])
    def set():
        flask.session["value"] = flask.request.form["value"]
        return "value set"

    @app.route("/get")
    def get():
        v = flask.session.get("value", "None")
        return v

    @app.route("/set_dynamic_cookie", methods=["POST"])
    def set_dynamic_cookie():
        flask.session["value"] = flask.request.form["value"]
        return "value set"

    @app.route("/get_dynamic_cookie")
    def get_dynamic_cookie():
        v = flask.session.get("value", "None")
        return v

    test_client = app.test_client()

    # first set the cookie in both /set urls but each with a different value
    assert test_client.post("/set", data={"value": "42"}).data == b"value set"
    assert (
        test_client.post("/set_dynamic_cookie", data={"value": "616"}).data
        == b"value set"
    )

    # now check that the relevant values come back - meaning that different
    # cookies are being used for the urls that end with "dynamic cookie"
    assert test_client.get("/get").data == b"42"
    assert test_client.get("/get_dynamic_cookie").data == b"616"


def test_bad_environ_raises_bad_request():
    app = flask.Flask(__name__)

    from flask.testing import EnvironBuilder

    builder = EnvironBuilder(app)
    environ = builder.get_environ()

    # use a non-printable character in the Host - this is key to this test
    environ["HTTP_HOST"] = "\x8a"

    with app.request_context(environ):
        response = app.full_dispatch_request()
    assert response.status_code == 400


def test_environ_for_valid_idna_completes():
    app = flask.Flask(__name__)

    @app.route("/")
    def index():
        return "Hello World!"

    from flask.testing import EnvironBuilder

    builder = EnvironBuilder(app)
    environ = builder.get_environ()

    # these characters are all IDNA-compatible
    environ["HTTP_HOST"] = "ąśźäüжŠßя.com"

    with app.request_context(environ):
        response = app.full_dispatch_request()

    assert response.status_code == 200


def test_normal_environ_completes():
    app = flask.Flask(__name__)

    @app.route("/")
    def index():
        return "Hello World!"

    response = app.test_client().get("/", headers={"host": "xn--on-0ia.com"})
    assert response.status_code == 200


Filepath: githubCode\tests\test_session_interface.py:

import flask
from flask.globals import request_ctx
from flask.sessions import SessionInterface


def test_open_session_with_endpoint():
    """If request.endpoint (or other URL matching behavior) is needed
    while loading the session, RequestContext.match_request() can be
    called manually.
    """

    class MySessionInterface(SessionInterface):
        def save_session(self, app, session, response):
            pass

        def open_session(self, app, request):
            request_ctx.match_request()
            assert request.endpoint is not None

    app = flask.Flask(__name__)
    app.session_interface = MySessionInterface()

    @app.get("/")
    def index():
        return "Hello, World!"

    response = app.test_client().get("/")
    assert response.status_code == 200


Filepath: githubCode\tests\test_signals.py:

import flask


def test_template_rendered(app, client):
    @app.route("/")
    def index():
        return flask.render_template("simple_template.html", whiskey=42)

    recorded = []

    def record(sender, template, context):
        recorded.append((template, context))

    flask.template_rendered.connect(record, app)
    try:
        client.get("/")
        assert len(recorded) == 1
        template, context = recorded[0]
        assert template.name == "simple_template.html"
        assert context["whiskey"] == 42
    finally:
        flask.template_rendered.disconnect(record, app)


def test_before_render_template():
    app = flask.Flask(__name__)

    @app.route("/")
    def index():
        return flask.render_template("simple_template.html", whiskey=42)

    recorded = []

    def record(sender, template, context):
        context["whiskey"] = 43
        recorded.append((template, context))

    flask.before_render_template.connect(record, app)
    try:
        rv = app.test_client().get("/")
        assert len(recorded) == 1
        template, context = recorded[0]
        assert template.name == "simple_template.html"
        assert context["whiskey"] == 43
        assert rv.data == b"<h1>43</h1>"
    finally:
        flask.before_render_template.disconnect(record, app)


def test_request_signals():
    app = flask.Flask(__name__)
    calls = []

    def before_request_signal(sender):
        calls.append("before-signal")

    def after_request_signal(sender, response):
        assert response.data == b"stuff"
        calls.append("after-signal")

    @app.before_request
    def before_request_handler():
        calls.append("before-handler")

    @app.after_request
    def after_request_handler(response):
        calls.append("after-handler")
        response.data = "stuff"
        return response

    @app.route("/")
    def index():
        calls.append("handler")
        return "ignored anyway"

    flask.request_started.connect(before_request_signal, app)
    flask.request_finished.connect(after_request_signal, app)

    try:
        rv = app.test_client().get("/")
        assert rv.data == b"stuff"

        assert calls == [
            "before-signal",
            "before-handler",
            "handler",
            "after-handler",
            "after-signal",
        ]
    finally:
        flask.request_started.disconnect(before_request_signal, app)
        flask.request_finished.disconnect(after_request_signal, app)


def test_request_exception_signal():
    app = flask.Flask(__name__)
    recorded = []

    @app.route("/")
    def index():
        raise ZeroDivisionError

    def record(sender, exception):
        recorded.append(exception)

    flask.got_request_exception.connect(record, app)
    try:
        assert app.test_client().get("/").status_code == 500
        assert len(recorded) == 1
        assert isinstance(recorded[0], ZeroDivisionError)
    finally:
        flask.got_request_exception.disconnect(record, app)


def test_appcontext_signals(app, client):
    recorded = []

    def record_push(sender, **kwargs):
        recorded.append("push")

    def record_pop(sender, **kwargs):
        recorded.append("pop")

    @app.route("/")
    def index():
        return "Hello"

    flask.appcontext_pushed.connect(record_push, app)
    flask.appcontext_popped.connect(record_pop, app)
    try:
        rv = client.get("/")
        assert rv.data == b"Hello"
        assert recorded == ["push", "pop"]
    finally:
        flask.appcontext_pushed.disconnect(record_push, app)
        flask.appcontext_popped.disconnect(record_pop, app)


def test_flash_signal(app):
    @app.route("/")
    def index():
        flask.flash("This is a flash message", category="notice")
        return flask.redirect("/other")

    recorded = []

    def record(sender, message, category):
        recorded.append((message, category))

    flask.message_flashed.connect(record, app)
    try:
        client = app.test_client()
        with client.session_transaction():
            client.get("/")
            assert len(recorded) == 1
            message, category = recorded[0]
            assert message == "This is a flash message"
            assert category == "notice"
    finally:
        flask.message_flashed.disconnect(record, app)


def test_appcontext_tearing_down_signal(app, client):
    app.testing = False
    recorded = []

    def record_teardown(sender, exc):
        recorded.append(exc)

    @app.route("/")
    def index():
        raise ZeroDivisionError

    flask.appcontext_tearing_down.connect(record_teardown, app)
    try:
        rv = client.get("/")
        assert rv.status_code == 500
        assert len(recorded) == 1
        assert isinstance(recorded[0], ZeroDivisionError)
    finally:
        flask.appcontext_tearing_down.disconnect(record_teardown, app)


Filepath: githubCode\tests\test_subclassing.py:

from io import StringIO

import flask


def test_suppressed_exception_logging():
    class SuppressedFlask(flask.Flask):
        def log_exception(self, exc_info):
            pass

    out = StringIO()
    app = SuppressedFlask(__name__)

    @app.route("/")
    def index():
        raise Exception("test")

    rv = app.test_client().get("/", errors_stream=out)
    assert rv.status_code == 500
    assert b"Internal Server Error" in rv.data
    assert not out.getvalue()


Filepath: githubCode\tests\test_templating.py:

import logging

import pytest
import werkzeug.serving
from jinja2 import TemplateNotFound
from markupsafe import Markup

import flask


def test_context_processing(app, client):
    @app.context_processor
    def context_processor():
        return {"injected_value": 42}

    @app.route("/")
    def index():
        return flask.render_template("context_template.html", value=23)

    rv = client.get("/")
    assert rv.data == b"<p>23|42"


def test_original_win(app, client):
    @app.route("/")
    def index():
        return flask.render_template_string("{{ config }}", config=42)

    rv = client.get("/")
    assert rv.data == b"42"


def test_simple_stream(app, client):
    @app.route("/")
    def index():
        return flask.stream_template_string("{{ config }}", config=42)

    rv = client.get("/")
    assert rv.data == b"42"


def test_request_less_rendering(app, app_ctx):
    app.config["WORLD_NAME"] = "Special World"

    @app.context_processor
    def context_processor():
        return dict(foo=42)

    rv = flask.render_template_string("Hello {{ config.WORLD_NAME }} {{ foo }}")
    assert rv == "Hello Special World 42"


def test_standard_context(app, client):
    @app.route("/")
    def index():
        flask.g.foo = 23
        flask.session["test"] = "aha"
        return flask.render_template_string(
            """
            {{ request.args.foo }}
            {{ g.foo }}
            {{ config.DEBUG }}
            {{ session.test }}
        """
        )

    rv = client.get("/?foo=42")
    assert rv.data.split() == [b"42", b"23", b"False", b"aha"]


def test_escaping(app, client):
    text = "<p>Hello World!"

    @app.route("/")
    def index():
        return flask.render_template(
            "escaping_template.html", text=text, html=Markup(text)
        )

    lines = client.get("/").data.splitlines()
    assert lines == [
        b"&lt;p&gt;Hello World!",
        b"<p>Hello World!",
        b"<p>Hello World!",
        b"<p>Hello World!",
        b"&lt;p&gt;Hello World!",
        b"<p>Hello World!",
    ]


def test_no_escaping(app, client):
    text = "<p>Hello World!"

    @app.route("/")
    def index():
        return flask.render_template(
            "non_escaping_template.txt", text=text, html=Markup(text)
        )

    lines = client.get("/").data.splitlines()
    assert lines == [
        b"<p>Hello World!",
        b"<p>Hello World!",
        b"<p>Hello World!",
        b"<p>Hello World!",
        b"&lt;p&gt;Hello World!",
        b"<p>Hello World!",
        b"<p>Hello World!",
        b"<p>Hello World!",
    ]


def test_escaping_without_template_filename(app, client, req_ctx):
    assert flask.render_template_string("{{ foo }}", foo="<test>") == "&lt;test&gt;"
    assert flask.render_template("mail.txt", foo="<test>") == "<test> Mail"


def test_macros(app, req_ctx):
    macro = flask.get_template_attribute("_macro.html", "hello")
    assert macro("World") == "Hello World!"


def test_template_filter(app):
    @app.template_filter()
    def my_reverse(s):
        return s[::-1]

    assert "my_reverse" in app.jinja_env.filters.keys()
    assert app.jinja_env.filters["my_reverse"] == my_reverse
    assert app.jinja_env.filters["my_reverse"]("abcd") == "dcba"


def test_add_template_filter(app):
    def my_reverse(s):
        return s[::-1]

    app.add_template_filter(my_reverse)
    assert "my_reverse" in app.jinja_env.filters.keys()
    assert app.jinja_env.filters["my_reverse"] == my_reverse
    assert app.jinja_env.filters["my_reverse"]("abcd") == "dcba"


def test_template_filter_with_name(app):
    @app.template_filter("strrev")
    def my_reverse(s):
        return s[::-1]

    assert "strrev" in app.jinja_env.filters.keys()
    assert app.jinja_env.filters["strrev"] == my_reverse
    assert app.jinja_env.filters["strrev"]("abcd") == "dcba"


def test_add_template_filter_with_name(app):
    def my_reverse(s):
        return s[::-1]

    app.add_template_filter(my_reverse, "strrev")
    assert "strrev" in app.jinja_env.filters.keys()
    assert app.jinja_env.filters["strrev"] == my_reverse
    assert app.jinja_env.filters["strrev"]("abcd") == "dcba"


def test_template_filter_with_template(app, client):
    @app.template_filter()
    def super_reverse(s):
        return s[::-1]

    @app.route("/")
    def index():
        return flask.render_template("template_filter.html", value="abcd")

    rv = client.get("/")
    assert rv.data == b"dcba"


def test_add_template_filter_with_template(app, client):
    def super_reverse(s):
        return s[::-1]

    app.add_template_filter(super_reverse)

    @app.route("/")
    def index():
        return flask.render_template("template_filter.html", value="abcd")

    rv = client.get("/")
    assert rv.data == b"dcba"


def test_template_filter_with_name_and_template(app, client):
    @app.template_filter("super_reverse")
    def my_reverse(s):
        return s[::-1]

    @app.route("/")
    def index():
        return flask.render_template("template_filter.html", value="abcd")

    rv = client.get("/")
    assert rv.data == b"dcba"


def test_add_template_filter_with_name_and_template(app, client):
    def my_reverse(s):
        return s[::-1]

    app.add_template_filter(my_reverse, "super_reverse")

    @app.route("/")
    def index():
        return flask.render_template("template_filter.html", value="abcd")

    rv = client.get("/")
    assert rv.data == b"dcba"


def test_template_test(app):
    @app.template_test()
    def boolean(value):
        return isinstance(value, bool)

    assert "boolean" in app.jinja_env.tests.keys()
    assert app.jinja_env.tests["boolean"] == boolean
    assert app.jinja_env.tests["boolean"](False)


def test_add_template_test(app):
    def boolean(value):
        return isinstance(value, bool)

    app.add_template_test(boolean)
    assert "boolean" in app.jinja_env.tests.keys()
    assert app.jinja_env.tests["boolean"] == boolean
    assert app.jinja_env.tests["boolean"](False)


def test_template_test_with_name(app):
    @app.template_test("boolean")
    def is_boolean(value):
        return isinstance(value, bool)

    assert "boolean" in app.jinja_env.tests.keys()
    assert app.jinja_env.tests["boolean"] == is_boolean
    assert app.jinja_env.tests["boolean"](False)


def test_add_template_test_with_name(app):
    def is_boolean(value):
        return isinstance(value, bool)

    app.add_template_test(is_boolean, "boolean")
    assert "boolean" in app.jinja_env.tests.keys()
    assert app.jinja_env.tests["boolean"] == is_boolean
    assert app.jinja_env.tests["boolean"](False)


def test_template_test_with_template(app, client):
    @app.template_test()
    def boolean(value):
        return isinstance(value, bool)

    @app.route("/")
    def index():
        return flask.render_template("template_test.html", value=False)

    rv = client.get("/")
    assert b"Success!" in rv.data


def test_add_template_test_with_template(app, client):
    def boolean(value):
        return isinstance(value, bool)

    app.add_template_test(boolean)

    @app.route("/")
    def index():
        return flask.render_template("template_test.html", value=False)

    rv = client.get("/")
    assert b"Success!" in rv.data


def test_template_test_with_name_and_template(app, client):
    @app.template_test("boolean")
    def is_boolean(value):
        return isinstance(value, bool)

    @app.route("/")
    def index():
        return flask.render_template("template_test.html", value=False)

    rv = client.get("/")
    assert b"Success!" in rv.data


def test_add_template_test_with_name_and_template(app, client):
    def is_boolean(value):
        return isinstance(value, bool)

    app.add_template_test(is_boolean, "boolean")

    @app.route("/")
    def index():
        return flask.render_template("template_test.html", value=False)

    rv = client.get("/")
    assert b"Success!" in rv.data


def test_add_template_global(app, app_ctx):
    @app.template_global()
    def get_stuff():
        return 42

    assert "get_stuff" in app.jinja_env.globals.keys()
    assert app.jinja_env.globals["get_stuff"] == get_stuff
    assert app.jinja_env.globals["get_stuff"](), 42

    rv = flask.render_template_string("{{ get_stuff() }}")
    assert rv == "42"


def test_custom_template_loader(client):
    class MyFlask(flask.Flask):
        def create_global_jinja_loader(self):
            from jinja2 import DictLoader

            return DictLoader({"index.html": "Hello Custom World!"})

    app = MyFlask(__name__)

    @app.route("/")
    def index():
        return flask.render_template("index.html")

    c = app.test_client()
    rv = c.get("/")
    assert rv.data == b"Hello Custom World!"


def test_iterable_loader(app, client):
    @app.context_processor
    def context_processor():
        return {"whiskey": "Jameson"}

    @app.route("/")
    def index():
        return flask.render_template(
            [
                "no_template.xml",  # should skip this one
                "simple_template.html",  # should render this
                "context_template.html",
            ],
            value=23,
        )

    rv = client.get("/")
    assert rv.data == b"<h1>Jameson</h1>"


def test_templates_auto_reload(app):
    # debug is False, config option is None
    assert app.debug is False
    assert app.config["TEMPLATES_AUTO_RELOAD"] is None
    assert app.jinja_env.auto_reload is False
    # debug is False, config option is False
    app = flask.Flask(__name__)
    app.config["TEMPLATES_AUTO_RELOAD"] = False
    assert app.debug is False
    assert app.jinja_env.auto_reload is False
    # debug is False, config option is True
    app = flask.Flask(__name__)
    app.config["TEMPLATES_AUTO_RELOAD"] = True
    assert app.debug is False
    assert app.jinja_env.auto_reload is True
    # debug is True, config option is None
    app = flask.Flask(__name__)
    app.config["DEBUG"] = True
    assert app.config["TEMPLATES_AUTO_RELOAD"] is None
    assert app.jinja_env.auto_reload is True
    # debug is True, config option is False
    app = flask.Flask(__name__)
    app.config["DEBUG"] = True
    app.config["TEMPLATES_AUTO_RELOAD"] = False
    assert app.jinja_env.auto_reload is False
    # debug is True, config option is True
    app = flask.Flask(__name__)
    app.config["DEBUG"] = True
    app.config["TEMPLATES_AUTO_RELOAD"] = True
    assert app.jinja_env.auto_reload is True


def test_templates_auto_reload_debug_run(app, monkeypatch):
    def run_simple_mock(*args, **kwargs):
        pass

    monkeypatch.setattr(werkzeug.serving, "run_simple", run_simple_mock)

    app.run()
    assert not app.jinja_env.auto_reload

    app.run(debug=True)
    assert app.jinja_env.auto_reload


def test_template_loader_debugging(test_apps, monkeypatch):
    from blueprintapp import app

    called = []

    class _TestHandler(logging.Handler):
        def handle(self, record):
            called.append(True)
            text = str(record.msg)
            assert "1: trying loader of application 'blueprintapp'" in text
            assert (
                "2: trying loader of blueprint 'admin' (blueprintapp.apps.admin)"
            ) in text
            assert (
                "trying loader of blueprint 'frontend' (blueprintapp.apps.frontend)"
            ) in text
            assert "Error: the template could not be found" in text
            assert (
                "looked up from an endpoint that belongs to the blueprint 'frontend'"
            ) in text
            assert "See https://flask.palletsprojects.com/blueprints/#templates" in text

    with app.test_client() as c:
        monkeypatch.setitem(app.config, "EXPLAIN_TEMPLATE_LOADING", True)
        monkeypatch.setattr(
            logging.getLogger("blueprintapp"), "handlers", [_TestHandler()]
        )

        with pytest.raises(TemplateNotFound) as excinfo:
            c.get("/missing")

        assert "missing_template.html" in str(excinfo.value)

    assert len(called) == 1


def test_custom_jinja_env():
    class CustomEnvironment(flask.templating.Environment):
        pass

    class CustomFlask(flask.Flask):
        jinja_environment = CustomEnvironment

    app = CustomFlask(__name__)
    assert isinstance(app.jinja_env, CustomEnvironment)


Filepath: githubCode\tests\test_testing.py:

import importlib.metadata

import click
import pytest

import flask
from flask import appcontext_popped
from flask.cli import ScriptInfo
from flask.globals import _cv_request
from flask.json import jsonify
from flask.testing import EnvironBuilder
from flask.testing import FlaskCliRunner


def test_environ_defaults_from_config(app, client):
    app.config["SERVER_NAME"] = "example.com:1234"
    app.config["APPLICATION_ROOT"] = "/foo"

    @app.route("/")
    def index():
        return flask.request.url

    ctx = app.test_request_context()
    assert ctx.request.url == "http://example.com:1234/foo/"

    rv = client.get("/")
    assert rv.data == b"http://example.com:1234/foo/"


def test_environ_defaults(app, client, app_ctx, req_ctx):
    @app.route("/")
    def index():
        return flask.request.url

    ctx = app.test_request_context()
    assert ctx.request.url == "http://localhost/"
    with client:
        rv = client.get("/")
        assert rv.data == b"http://localhost/"


def test_environ_base_default(app, client):
    @app.route("/")
    def index():
        flask.g.remote_addr = flask.request.remote_addr
        flask.g.user_agent = flask.request.user_agent.string
        return ""

    with client:
        client.get("/")
        assert flask.g.remote_addr == "127.0.0.1"
        assert flask.g.user_agent == (
            f"Werkzeug/{importlib.metadata.version('werkzeug')}"
        )


def test_environ_base_modified(app, client):
    @app.route("/")
    def index():
        flask.g.remote_addr = flask.request.remote_addr
        flask.g.user_agent = flask.request.user_agent.string
        return ""

    client.environ_base["REMOTE_ADDR"] = "192.168.0.22"
    client.environ_base["HTTP_USER_AGENT"] = "Foo"

    with client:
        client.get("/")
        assert flask.g.remote_addr == "192.168.0.22"
        assert flask.g.user_agent == "Foo"


def test_client_open_environ(app, client, request):
    @app.route("/index")
    def index():
        return flask.request.remote_addr

    builder = EnvironBuilder(app, path="/index", method="GET")
    request.addfinalizer(builder.close)

    rv = client.open(builder)
    assert rv.data == b"127.0.0.1"

    environ = builder.get_environ()
    client.environ_base["REMOTE_ADDR"] = "127.0.0.2"
    rv = client.open(environ)
    assert rv.data == b"127.0.0.2"


def test_specify_url_scheme(app, client):
    @app.route("/")
    def index():
        return flask.request.url

    ctx = app.test_request_context(url_scheme="https")
    assert ctx.request.url == "https://localhost/"

    rv = client.get("/", url_scheme="https")
    assert rv.data == b"https://localhost/"


def test_path_is_url(app):
    eb = EnvironBuilder(app, "https://example.com/")
    assert eb.url_scheme == "https"
    assert eb.host == "example.com"
    assert eb.script_root == ""
    assert eb.path == "/"


def test_environbuilder_json_dumps(app):
    """EnvironBuilder.json_dumps() takes settings from the app."""
    app.json.ensure_ascii = False
    eb = EnvironBuilder(app, json="\u20ac")
    assert eb.input_stream.read().decode("utf8") == '"\u20ac"'


def test_blueprint_with_subdomain():
    app = flask.Flask(__name__, subdomain_matching=True)
    app.config["SERVER_NAME"] = "example.com:1234"
    app.config["APPLICATION_ROOT"] = "/foo"
    client = app.test_client()

    bp = flask.Blueprint("company", __name__, subdomain="xxx")

    @bp.route("/")
    def index():
        return flask.request.url

    app.register_blueprint(bp)

    ctx = app.test_request_context("/", subdomain="xxx")
    assert ctx.request.url == "http://xxx.example.com:1234/foo/"

    with ctx:
        assert ctx.request.blueprint == bp.name

    rv = client.get("/", subdomain="xxx")
    assert rv.data == b"http://xxx.example.com:1234/foo/"


def test_redirect_keep_session(app, client, app_ctx):
    @app.route("/", methods=["GET", "POST"])
    def index():
        if flask.request.method == "POST":
            return flask.redirect("/getsession")
        flask.session["data"] = "foo"
        return "index"

    @app.route("/getsession")
    def get_session():
        return flask.session.get("data", "<missing>")

    with client:
        rv = client.get("/getsession")
        assert rv.data == b"<missing>"

        rv = client.get("/")
        assert rv.data == b"index"
        assert flask.session.get("data") == "foo"

        rv = client.post("/", data={}, follow_redirects=True)
        assert rv.data == b"foo"
        assert flask.session.get("data") == "foo"

        rv = client.get("/getsession")
        assert rv.data == b"foo"


def test_session_transactions(app, client):
    @app.route("/")
    def index():
        return str(flask.session["foo"])

    with client:
        with client.session_transaction() as sess:
            assert len(sess) == 0
            sess["foo"] = [42]
            assert len(sess) == 1
        rv = client.get("/")
        assert rv.data == b"[42]"
        with client.session_transaction() as sess:
            assert len(sess) == 1
            assert sess["foo"] == [42]


def test_session_transactions_no_null_sessions():
    app = flask.Flask(__name__)

    with app.test_client() as c:
        with pytest.raises(RuntimeError) as e:
            with c.session_transaction():
                pass
        assert "Session backend did not open a session" in str(e.value)


def test_session_transactions_keep_context(app, client, req_ctx):
    client.get("/")
    req = flask.request._get_current_object()
    assert req is not None
    with client.session_transaction():
        assert req is flask.request._get_current_object()


def test_session_transaction_needs_cookies(app):
    c = app.test_client(use_cookies=False)

    with pytest.raises(TypeError, match="Cookies are disabled."):
        with c.session_transaction():
            pass


def test_test_client_context_binding(app, client):
    app.testing = False

    @app.route("/")
    def index():
        flask.g.value = 42
        return "Hello World!"

    @app.route("/other")
    def other():
        raise ZeroDivisionError

    with client:
        resp = client.get("/")
        assert flask.g.value == 42
        assert resp.data == b"Hello World!"
        assert resp.status_code == 200

    with client:
        resp = client.get("/other")
        assert not hasattr(flask.g, "value")
        assert b"Internal Server Error" in resp.data
        assert resp.status_code == 500
        flask.g.value = 23

    with pytest.raises(RuntimeError):
        flask.g.value  # noqa: B018


def test_reuse_client(client):
    c = client

    with c:
        assert client.get("/").status_code == 404

    with c:
        assert client.get("/").status_code == 404


def test_full_url_request(app, client):
    @app.route("/action", methods=["POST"])
    def action():
        return "x"

    with client:
        rv = client.post("http://domain.com/action?vodka=42", data={"gin": 43})
        assert rv.status_code == 200
        assert "gin" in flask.request.form
        assert "vodka" in flask.request.args


def test_json_request_and_response(app, client):
    @app.route("/echo", methods=["POST"])
    def echo():
        return jsonify(flask.request.get_json())

    with client:
        json_data = {"drink": {"gin": 1, "tonic": True}, "price": 10}
        rv = client.post("/echo", json=json_data)

        # Request should be in JSON
        assert flask.request.is_json
        assert flask.request.get_json() == json_data

        # Response should be in JSON
        assert rv.status_code == 200
        assert rv.is_json
        assert rv.get_json() == json_data


def test_client_json_no_app_context(app, client):
    @app.route("/hello", methods=["POST"])
    def hello():
        return f"Hello, {flask.request.json['name']}!"

    class Namespace:
        count = 0

        def add(self, app):
            self.count += 1

    ns = Namespace()

    with appcontext_popped.connected_to(ns.add, app):
        rv = client.post("/hello", json={"name": "Flask"})

    assert rv.get_data(as_text=True) == "Hello, Flask!"
    assert ns.count == 1


def test_subdomain():
    app = flask.Flask(__name__, subdomain_matching=True)
    app.config["SERVER_NAME"] = "example.com"
    client = app.test_client()

    @app.route("/", subdomain="<company_id>")
    def view(company_id):
        return company_id

    with app.test_request_context():
        url = flask.url_for("view", company_id="xxx")

    with client:
        response = client.get(url)

    assert 200 == response.status_code
    assert b"xxx" == response.data


def test_nosubdomain(app, client):
    app.config["SERVER_NAME"] = "example.com"

    @app.route("/<company_id>")
    def view(company_id):
        return company_id

    with app.test_request_context():
        url = flask.url_for("view", company_id="xxx")

    with client:
        response = client.get(url)

    assert 200 == response.status_code
    assert b"xxx" == response.data


def test_cli_runner_class(app):
    runner = app.test_cli_runner()
    assert isinstance(runner, FlaskCliRunner)

    class SubRunner(FlaskCliRunner):
        pass

    app.test_cli_runner_class = SubRunner
    runner = app.test_cli_runner()
    assert isinstance(runner, SubRunner)


def test_cli_invoke(app):
    @app.cli.command("hello")
    def hello_command():
        click.echo("Hello, World!")

    runner = app.test_cli_runner()
    # invoke with command name
    result = runner.invoke(args=["hello"])
    assert "Hello" in result.output
    # invoke with command object
    result = runner.invoke(hello_command)
    assert "Hello" in result.output


def test_cli_custom_obj(app):
    class NS:
        called = False

    def create_app():
        NS.called = True
        return app

    @app.cli.command("hello")
    def hello_command():
        click.echo("Hello, World!")

    script_info = ScriptInfo(create_app=create_app)
    runner = app.test_cli_runner()
    runner.invoke(hello_command, obj=script_info)
    assert NS.called


def test_client_pop_all_preserved(app, req_ctx, client):
    @app.route("/")
    def index():
        # stream_with_context pushes a third context, preserved by response
        return flask.stream_with_context("hello")

    # req_ctx fixture pushed an initial context
    with client:
        # request pushes a second request context, preserved by client
        rv = client.get("/")

    # close the response, releasing the context held by stream_with_context
    rv.close()
    # only req_ctx fixture should still be pushed
    assert _cv_request.get(None) is req_ctx


Filepath: githubCode\tests\test_user_error_handler.py:

import pytest
from werkzeug.exceptions import Forbidden
from werkzeug.exceptions import HTTPException
from werkzeug.exceptions import InternalServerError
from werkzeug.exceptions import NotFound

import flask


def test_error_handler_no_match(app, client):
    class CustomException(Exception):
        pass

    @app.errorhandler(CustomException)
    def custom_exception_handler(e):
        assert isinstance(e, CustomException)
        return "custom"

    with pytest.raises(TypeError) as exc_info:
        app.register_error_handler(CustomException(), None)

    assert "CustomException() is an instance, not a class." in str(exc_info.value)

    with pytest.raises(ValueError) as exc_info:
        app.register_error_handler(list, None)

    assert "'list' is not a subclass of Exception." in str(exc_info.value)

    @app.errorhandler(500)
    def handle_500(e):
        assert isinstance(e, InternalServerError)

        if e.original_exception is not None:
            return f"wrapped {type(e.original_exception).__name__}"

        return "direct"

    with pytest.raises(ValueError) as exc_info:
        app.register_error_handler(999, None)

    assert "Use a subclass of HTTPException" in str(exc_info.value)

    @app.route("/custom")
    def custom_test():
        raise CustomException()

    @app.route("/keyerror")
    def key_error():
        raise KeyError()

    @app.route("/abort")
    def do_abort():
        flask.abort(500)

    app.testing = False
    assert client.get("/custom").data == b"custom"
    assert client.get("/keyerror").data == b"wrapped KeyError"
    assert client.get("/abort").data == b"direct"


def test_error_handler_subclass(app):
    class ParentException(Exception):
        pass

    class ChildExceptionUnregistered(ParentException):
        pass

    class ChildExceptionRegistered(ParentException):
        pass

    @app.errorhandler(ParentException)
    def parent_exception_handler(e):
        assert isinstance(e, ParentException)
        return "parent"

    @app.errorhandler(ChildExceptionRegistered)
    def child_exception_handler(e):
        assert isinstance(e, ChildExceptionRegistered)
        return "child-registered"

    @app.route("/parent")
    def parent_test():
        raise ParentException()

    @app.route("/child-unregistered")
    def unregistered_test():
        raise ChildExceptionUnregistered()

    @app.route("/child-registered")
    def registered_test():
        raise ChildExceptionRegistered()

    c = app.test_client()

    assert c.get("/parent").data == b"parent"
    assert c.get("/child-unregistered").data == b"parent"
    assert c.get("/child-registered").data == b"child-registered"


def test_error_handler_http_subclass(app):
    class ForbiddenSubclassRegistered(Forbidden):
        pass

    class ForbiddenSubclassUnregistered(Forbidden):
        pass

    @app.errorhandler(403)
    def code_exception_handler(e):
        assert isinstance(e, Forbidden)
        return "forbidden"

    @app.errorhandler(ForbiddenSubclassRegistered)
    def subclass_exception_handler(e):
        assert isinstance(e, ForbiddenSubclassRegistered)
        return "forbidden-registered"

    @app.route("/forbidden")
    def forbidden_test():
        raise Forbidden()

    @app.route("/forbidden-registered")
    def registered_test():
        raise ForbiddenSubclassRegistered()

    @app.route("/forbidden-unregistered")
    def unregistered_test():
        raise ForbiddenSubclassUnregistered()

    c = app.test_client()

    assert c.get("/forbidden").data == b"forbidden"
    assert c.get("/forbidden-unregistered").data == b"forbidden"
    assert c.get("/forbidden-registered").data == b"forbidden-registered"


def test_error_handler_blueprint(app):
    bp = flask.Blueprint("bp", __name__)

    @bp.errorhandler(500)
    def bp_exception_handler(e):
        return "bp-error"

    @bp.route("/error")
    def bp_test():
        raise InternalServerError()

    @app.errorhandler(500)
    def app_exception_handler(e):
        return "app-error"

    @app.route("/error")
    def app_test():
        raise InternalServerError()

    app.register_blueprint(bp, url_prefix="/bp")

    c = app.test_client()

    assert c.get("/error").data == b"app-error"
    assert c.get("/bp/error").data == b"bp-error"


def test_default_error_handler():
    bp = flask.Blueprint("bp", __name__)

    @bp.errorhandler(HTTPException)
    def bp_exception_handler(e):
        assert isinstance(e, HTTPException)
        assert isinstance(e, NotFound)
        return "bp-default"

    @bp.errorhandler(Forbidden)
    def bp_forbidden_handler(e):
        assert isinstance(e, Forbidden)
        return "bp-forbidden"

    @bp.route("/undefined")
    def bp_registered_test():
        raise NotFound()

    @bp.route("/forbidden")
    def bp_forbidden_test():
        raise Forbidden()

    app = flask.Flask(__name__)

    @app.errorhandler(HTTPException)
    def catchall_exception_handler(e):
        assert isinstance(e, HTTPException)
        assert isinstance(e, NotFound)
        return "default"

    @app.errorhandler(Forbidden)
    def catchall_forbidden_handler(e):
        assert isinstance(e, Forbidden)
        return "forbidden"

    @app.route("/forbidden")
    def forbidden():
        raise Forbidden()

    @app.route("/slash/")
    def slash():
        return "slash"

    app.register_blueprint(bp, url_prefix="/bp")

    c = app.test_client()
    assert c.get("/bp/undefined").data == b"bp-default"
    assert c.get("/bp/forbidden").data == b"bp-forbidden"
    assert c.get("/undefined").data == b"default"
    assert c.get("/forbidden").data == b"forbidden"
    # Don't handle RequestRedirect raised when adding slash.
    assert c.get("/slash", follow_redirects=True).data == b"slash"


class TestGenericHandlers:
    """Test how very generic handlers are dispatched to."""

    class Custom(Exception):
        pass

    @pytest.fixture()
    def app(self, app):
        @app.route("/custom")
        def do_custom():
            raise self.Custom()

        @app.route("/error")
        def do_error():
            raise KeyError()

        @app.route("/abort")
        def do_abort():
            flask.abort(500)

        @app.route("/raise")
        def do_raise():
            raise InternalServerError()

        app.config["PROPAGATE_EXCEPTIONS"] = False
        return app

    def report_error(self, e):
        original = getattr(e, "original_exception", None)

        if original is not None:
            return f"wrapped {type(original).__name__}"

        return f"direct {type(e).__name__}"

    @pytest.mark.parametrize("to_handle", (InternalServerError, 500))
    def test_handle_class_or_code(self, app, client, to_handle):
        """``InternalServerError`` and ``500`` are aliases, they should
        have the same behavior. Both should only receive
        ``InternalServerError``, which might wrap another error.
        """

        @app.errorhandler(to_handle)
        def handle_500(e):
            assert isinstance(e, InternalServerError)
            return self.report_error(e)

        assert client.get("/custom").data == b"wrapped Custom"
        assert client.get("/error").data == b"wrapped KeyError"
        assert client.get("/abort").data == b"direct InternalServerError"
        assert client.get("/raise").data == b"direct InternalServerError"

    def test_handle_generic_http(self, app, client):
        """``HTTPException`` should only receive ``HTTPException``
        subclasses. It will receive ``404`` routing exceptions.
        """

        @app.errorhandler(HTTPException)
        def handle_http(e):
            assert isinstance(e, HTTPException)
            return str(e.code)

        assert client.get("/error").data == b"500"
        assert client.get("/abort").data == b"500"
        assert client.get("/not-found").data == b"404"

    def test_handle_generic(self, app, client):
        """Generic ``Exception`` will handle all exceptions directly,
        including ``HTTPExceptions``.
        """

        @app.errorhandler(Exception)
        def handle_exception(e):
            return self.report_error(e)

        assert client.get("/custom").data == b"direct Custom"
        assert client.get("/error").data == b"direct KeyError"
        assert client.get("/abort").data == b"direct InternalServerError"
        assert client.get("/not-found").data == b"direct NotFound"


Filepath: githubCode\tests\test_views.py:

import pytest
from werkzeug.http import parse_set_header

import flask.views


def common_test(app):
    c = app.test_client()

    assert c.get("/").data == b"GET"
    assert c.post("/").data == b"POST"
    assert c.put("/").status_code == 405
    meths = parse_set_header(c.open("/", method="OPTIONS").headers["Allow"])
    assert sorted(meths) == ["GET", "HEAD", "OPTIONS", "POST"]


def test_basic_view(app):
    class Index(flask.views.View):
        methods = ["GET", "POST"]

        def dispatch_request(self):
            return flask.request.method

    app.add_url_rule("/", view_func=Index.as_view("index"))
    common_test(app)


def test_method_based_view(app):
    class Index(flask.views.MethodView):
        def get(self):
            return "GET"

        def post(self):
            return "POST"

    app.add_url_rule("/", view_func=Index.as_view("index"))

    common_test(app)


def test_view_patching(app):
    class Index(flask.views.MethodView):
        def get(self):
            raise ZeroDivisionError

        def post(self):
            raise ZeroDivisionError

    class Other(Index):
        def get(self):
            return "GET"

        def post(self):
            return "POST"

    view = Index.as_view("index")
    view.view_class = Other
    app.add_url_rule("/", view_func=view)
    common_test(app)


def test_view_inheritance(app, client):
    class Index(flask.views.MethodView):
        def get(self):
            return "GET"

        def post(self):
            return "POST"

    class BetterIndex(Index):
        def delete(self):
            return "DELETE"

    app.add_url_rule("/", view_func=BetterIndex.as_view("index"))

    meths = parse_set_header(client.open("/", method="OPTIONS").headers["Allow"])
    assert sorted(meths) == ["DELETE", "GET", "HEAD", "OPTIONS", "POST"]


def test_view_decorators(app, client):
    def add_x_parachute(f):
        def new_function(*args, **kwargs):
            resp = flask.make_response(f(*args, **kwargs))
            resp.headers["X-Parachute"] = "awesome"
            return resp

        return new_function

    class Index(flask.views.View):
        decorators = [add_x_parachute]

        def dispatch_request(self):
            return "Awesome"

    app.add_url_rule("/", view_func=Index.as_view("index"))
    rv = client.get("/")
    assert rv.headers["X-Parachute"] == "awesome"
    assert rv.data == b"Awesome"


def test_view_provide_automatic_options_attr():
    app = flask.Flask(__name__)

    class Index1(flask.views.View):
        provide_automatic_options = False

        def dispatch_request(self):
            return "Hello World!"

    app.add_url_rule("/", view_func=Index1.as_view("index"))
    c = app.test_client()
    rv = c.open("/", method="OPTIONS")
    assert rv.status_code == 405

    app = flask.Flask(__name__)

    class Index2(flask.views.View):
        methods = ["OPTIONS"]
        provide_automatic_options = True

        def dispatch_request(self):
            return "Hello World!"

    app.add_url_rule("/", view_func=Index2.as_view("index"))
    c = app.test_client()
    rv = c.open("/", method="OPTIONS")
    assert sorted(rv.allow) == ["OPTIONS"]

    app = flask.Flask(__name__)

    class Index3(flask.views.View):
        def dispatch_request(self):
            return "Hello World!"

    app.add_url_rule("/", view_func=Index3.as_view("index"))
    c = app.test_client()
    rv = c.open("/", method="OPTIONS")
    assert "OPTIONS" in rv.allow


def test_implicit_head(app, client):
    class Index(flask.views.MethodView):
        def get(self):
            return flask.Response("Blub", headers={"X-Method": flask.request.method})

    app.add_url_rule("/", view_func=Index.as_view("index"))
    rv = client.get("/")
    assert rv.data == b"Blub"
    assert rv.headers["X-Method"] == "GET"
    rv = client.head("/")
    assert rv.data == b""
    assert rv.headers["X-Method"] == "HEAD"


def test_explicit_head(app, client):
    class Index(flask.views.MethodView):
        def get(self):
            return "GET"

        def head(self):
            return flask.Response("", headers={"X-Method": "HEAD"})

    app.add_url_rule("/", view_func=Index.as_view("index"))
    rv = client.get("/")
    assert rv.data == b"GET"
    rv = client.head("/")
    assert rv.data == b""
    assert rv.headers["X-Method"] == "HEAD"


def test_endpoint_override(app):
    app.debug = True

    class Index(flask.views.View):
        methods = ["GET", "POST"]

        def dispatch_request(self):
            return flask.request.method

    app.add_url_rule("/", view_func=Index.as_view("index"))

    with pytest.raises(AssertionError):
        app.add_url_rule("/", view_func=Index.as_view("index"))

    # But these tests should still pass. We just log a warning.
    common_test(app)


def test_methods_var_inheritance(app, client):
    class BaseView(flask.views.MethodView):
        methods = ["GET", "PROPFIND"]

    class ChildView(BaseView):
        def get(self):
            return "GET"

        def propfind(self):
            return "PROPFIND"

    app.add_url_rule("/", view_func=ChildView.as_view("index"))

    assert client.get("/").data == b"GET"
    assert client.open("/", method="PROPFIND").data == b"PROPFIND"
    assert ChildView.methods == {"PROPFIND", "GET"}


def test_multiple_inheritance(app, client):
    class GetView(flask.views.MethodView):
        def get(self):
            return "GET"

    class DeleteView(flask.views.MethodView):
        def delete(self):
            return "DELETE"

    class GetDeleteView(GetView, DeleteView):
        pass

    app.add_url_rule("/", view_func=GetDeleteView.as_view("index"))

    assert client.get("/").data == b"GET"
    assert client.delete("/").data == b"DELETE"
    assert sorted(GetDeleteView.methods) == ["DELETE", "GET"]


def test_remove_method_from_parent(app, client):
    class GetView(flask.views.MethodView):
        def get(self):
            return "GET"

    class OtherView(flask.views.MethodView):
        def post(self):
            return "POST"

    class View(GetView, OtherView):
        methods = ["GET"]

    app.add_url_rule("/", view_func=View.as_view("index"))

    assert client.get("/").data == b"GET"
    assert client.post("/").status_code == 405
    assert sorted(View.methods) == ["GET"]


def test_init_once(app, client):
    n = 0

    class CountInit(flask.views.View):
        init_every_request = False

        def __init__(self):
            nonlocal n
            n += 1

        def dispatch_request(self):
            return str(n)

    app.add_url_rule("/", view_func=CountInit.as_view("index"))
    assert client.get("/").data == b"1"
    assert client.get("/").data == b"1"


Filepath: githubCode\examples\celery\make_celery.py:

from task_app import create_app

flask_app = create_app()
celery_app = flask_app.extensions["celery"]


Filepath: githubCode\examples\celery\src\task_app\tasks.py:

import time

from celery import shared_task
from celery import Task


@shared_task(ignore_result=False)
def add(a: int, b: int) -> int:
    return a + b


@shared_task()
def block() -> None:
    time.sleep(5)


@shared_task(bind=True, ignore_result=False)
def process(self: Task, total: int) -> object:
    for i in range(total):
        self.update_state(state="PROGRESS", meta={"current": i + 1, "total": total})
        time.sleep(1)

    return {"current": total, "total": total}


Filepath: githubCode\examples\celery\src\task_app\views.py:

from celery.result import AsyncResult
from flask import Blueprint
from flask import request

from . import tasks

bp = Blueprint("tasks", __name__, url_prefix="/tasks")


@bp.get("/result/<id>")
def result(id: str) -> dict[str, object]:
    result = AsyncResult(id)
    ready = result.ready()
    return {
        "ready": ready,
        "successful": result.successful() if ready else None,
        "value": result.get() if ready else result.result,
    }


@bp.post("/add")
def add() -> dict[str, object]:
    a = request.form.get("a", type=int)
    b = request.form.get("b", type=int)
    result = tasks.add.delay(a, b)
    return {"result_id": result.id}


@bp.post("/block")
def block() -> dict[str, object]:
    result = tasks.block.delay()
    return {"result_id": result.id}


@bp.post("/process")
def process() -> dict[str, object]:
    result = tasks.process.delay(total=request.form.get("total", type=int))
    return {"result_id": result.id}


Filepath: githubCode\examples\celery\src\task_app\__init__.py:

from celery import Celery
from celery import Task
from flask import Flask
from flask import render_template


def create_app() -> Flask:
    app = Flask(__name__)
    app.config.from_mapping(
        CELERY=dict(
            broker_url="redis://localhost",
            result_backend="redis://localhost",
            task_ignore_result=True,
        ),
    )
    app.config.from_prefixed_env()
    celery_init_app(app)

    @app.route("/")
    def index() -> str:
        return render_template("index.html")

    from . import views

    app.register_blueprint(views.bp)
    return app


def celery_init_app(app: Flask) -> Celery:
    class FlaskTask(Task):
        def __call__(self, *args: object, **kwargs: object) -> object:
            with app.app_context():
                return self.run(*args, **kwargs)

    celery_app = Celery(app.name, task_cls=FlaskTask)
    celery_app.config_from_object(app.config["CELERY"])
    celery_app.set_default()
    app.extensions["celery"] = celery_app
    return celery_app


Filepath: githubCode\examples\javascript\js_example\views.py:

from flask import jsonify
from flask import render_template
from flask import request

from . import app


@app.route("/", defaults={"js": "fetch"})
@app.route("/<any(xhr, jquery, fetch):js>")
def index(js):
    return render_template(f"{js}.html", js=js)


@app.route("/add", methods=["POST"])
def add():
    a = request.form.get("a", 0, type=float)
    b = request.form.get("b", 0, type=float)
    return jsonify(result=a + b)


Filepath: githubCode\examples\javascript\js_example\__init__.py:

from flask import Flask

app = Flask(__name__)

from js_example import views  # noqa: E402, F401


Filepath: githubCode\examples\javascript\tests\conftest.py:

import pytest

from js_example import app


@pytest.fixture(name="app")
def fixture_app():
    app.testing = True
    yield app
    app.testing = False


@pytest.fixture
def client(app):
    return app.test_client()


Filepath: githubCode\examples\javascript\tests\test_js_example.py:

import pytest
from flask import template_rendered


@pytest.mark.parametrize(
    ("path", "template_name"),
    (
        ("/", "xhr.html"),
        ("/plain", "xhr.html"),
        ("/fetch", "fetch.html"),
        ("/jquery", "jquery.html"),
    ),
)
def test_index(app, client, path, template_name):
    def check(sender, template, context):
        assert template.name == template_name

    with template_rendered.connected_to(check, app):
        client.get(path)


@pytest.mark.parametrize(
    ("a", "b", "result"), ((2, 3, 5), (2.5, 3, 5.5), (2, None, 2), (2, "b", 2))
)
def test_add(client, a, b, result):
    response = client.post("/add", data={"a": a, "b": b})
    assert response.get_json()["result"] == result


Filepath: githubCode\examples\tutorial\flaskr\auth.py:

import functools

from flask import Blueprint
from flask import flash
from flask import g
from flask import redirect
from flask import render_template
from flask import request
from flask import session
from flask import url_for
from werkzeug.security import check_password_hash
from werkzeug.security import generate_password_hash

from .db import get_db

bp = Blueprint("auth", __name__, url_prefix="/auth")


def login_required(view):
    """View decorator that redirects anonymous users to the login page."""

    @functools.wraps(view)
    def wrapped_view(**kwargs):
        if g.user is None:
            return redirect(url_for("auth.login"))

        return view(**kwargs)

    return wrapped_view


@bp.before_app_request
def load_logged_in_user():
    """If a user id is stored in the session, load the user object from
    the database into ``g.user``."""
    user_id = session.get("user_id")

    if user_id is None:
        g.user = None
    else:
        g.user = (
            get_db().execute("SELECT * FROM user WHERE id = ?", (user_id,)).fetchone()
        )


@bp.route("/register", methods=("GET", "POST"))
def register():
    """Register a new user.

    Validates that the username is not already taken. Hashes the
    password for security.
    """
    if request.method == "POST":
        username = request.form["username"]
        password = request.form["password"]
        db = get_db()
        error = None

        if not username:
            error = "Username is required."
        elif not password:
            error = "Password is required."

        if error is None:
            try:
                db.execute(
                    "INSERT INTO user (username, password) VALUES (?, ?)",
                    (username, generate_password_hash(password)),
                )
                db.commit()
            except db.IntegrityError:
                # The username was already taken, which caused the
                # commit to fail. Show a validation error.
                error = f"User {username} is already registered."
            else:
                # Success, go to the login page.
                return redirect(url_for("auth.login"))

        flash(error)

    return render_template("auth/register.html")


@bp.route("/login", methods=("GET", "POST"))
def login():
    """Log in a registered user by adding the user id to the session."""
    if request.method == "POST":
        username = request.form["username"]
        password = request.form["password"]
        db = get_db()
        error = None
        user = db.execute(
            "SELECT * FROM user WHERE username = ?", (username,)
        ).fetchone()

        if user is None:
            error = "Incorrect username."
        elif not check_password_hash(user["password"], password):
            error = "Incorrect password."

        if error is None:
            # store the user id in a new session and return to the index
            session.clear()
            session["user_id"] = user["id"]
            return redirect(url_for("index"))

        flash(error)

    return render_template("auth/login.html")


@bp.route("/logout")
def logout():
    """Clear the current session, including the stored user id."""
    session.clear()
    return redirect(url_for("index"))


Filepath: githubCode\examples\tutorial\flaskr\blog.py:

from flask import Blueprint
from flask import flash
from flask import g
from flask import redirect
from flask import render_template
from flask import request
from flask import url_for
from werkzeug.exceptions import abort

from .auth import login_required
from .db import get_db

bp = Blueprint("blog", __name__)


@bp.route("/")
def index():
    """Show all the posts, most recent first."""
    db = get_db()
    posts = db.execute(
        "SELECT p.id, title, body, created, author_id, username"
        " FROM post p JOIN user u ON p.author_id = u.id"
        " ORDER BY created DESC"
    ).fetchall()
    return render_template("blog/index.html", posts=posts)


def get_post(id, check_author=True):
    """Get a post and its author by id.

    Checks that the id exists and optionally that the current user is
    the author.

    :param id: id of post to get
    :param check_author: require the current user to be the author
    :return: the post with author information
    :raise 404: if a post with the given id doesn't exist
    :raise 403: if the current user isn't the author
    """
    post = (
        get_db()
        .execute(
            "SELECT p.id, title, body, created, author_id, username"
            " FROM post p JOIN user u ON p.author_id = u.id"
            " WHERE p.id = ?",
            (id,),
        )
        .fetchone()
    )

    if post is None:
        abort(404, f"Post id {id} doesn't exist.")

    if check_author and post["author_id"] != g.user["id"]:
        abort(403)

    return post


@bp.route("/create", methods=("GET", "POST"))
@login_required
def create():
    """Create a new post for the current user."""
    if request.method == "POST":
        title = request.form["title"]
        body = request.form["body"]
        error = None

        if not title:
            error = "Title is required."

        if error is not None:
            flash(error)
        else:
            db = get_db()
            db.execute(
                "INSERT INTO post (title, body, author_id) VALUES (?, ?, ?)",
                (title, body, g.user["id"]),
            )
            db.commit()
            return redirect(url_for("blog.index"))

    return render_template("blog/create.html")


@bp.route("/<int:id>/update", methods=("GET", "POST"))
@login_required
def update(id):
    """Update a post if the current user is the author."""
    post = get_post(id)

    if request.method == "POST":
        title = request.form["title"]
        body = request.form["body"]
        error = None

        if not title:
            error = "Title is required."

        if error is not None:
            flash(error)
        else:
            db = get_db()
            db.execute(
                "UPDATE post SET title = ?, body = ? WHERE id = ?", (title, body, id)
            )
            db.commit()
            return redirect(url_for("blog.index"))

    return render_template("blog/update.html", post=post)


@bp.route("/<int:id>/delete", methods=("POST",))
@login_required
def delete(id):
    """Delete a post.

    Ensures that the post exists and that the logged in user is the
    author of the post.
    """
    get_post(id)
    db = get_db()
    db.execute("DELETE FROM post WHERE id = ?", (id,))
    db.commit()
    return redirect(url_for("blog.index"))


Filepath: githubCode\examples\tutorial\flaskr\db.py:

import sqlite3

import click
from flask import current_app
from flask import g


def get_db():
    """Connect to the application's configured database. The connection
    is unique for each request and will be reused if this is called
    again.
    """
    if "db" not in g:
        g.db = sqlite3.connect(
            current_app.config["DATABASE"], detect_types=sqlite3.PARSE_DECLTYPES
        )
        g.db.row_factory = sqlite3.Row

    return g.db


def close_db(e=None):
    """If this request connected to the database, close the
    connection.
    """
    db = g.pop("db", None)

    if db is not None:
        db.close()


def init_db():
    """Clear existing data and create new tables."""
    db = get_db()

    with current_app.open_resource("schema.sql") as f:
        db.executescript(f.read().decode("utf8"))


@click.command("init-db")
def init_db_command():
    """Clear existing data and create new tables."""
    init_db()
    click.echo("Initialized the database.")


def init_app(app):
    """Register database functions with the Flask app. This is called by
    the application factory.
    """
    app.teardown_appcontext(close_db)
    app.cli.add_command(init_db_command)


Filepath: githubCode\examples\tutorial\flaskr\__init__.py:

import os

from flask import Flask


def create_app(test_config=None):
    """Create and configure an instance of the Flask application."""
    app = Flask(__name__, instance_relative_config=True)
    app.config.from_mapping(
        # a default secret that should be overridden by instance config
        SECRET_KEY="dev",
        # store the database in the instance folder
        DATABASE=os.path.join(app.instance_path, "flaskr.sqlite"),
    )

    if test_config is None:
        # load the instance config, if it exists, when not testing
        app.config.from_pyfile("config.py", silent=True)
    else:
        # load the test config if passed in
        app.config.update(test_config)

    # ensure the instance folder exists
    try:
        os.makedirs(app.instance_path)
    except OSError:
        pass

    @app.route("/hello")
    def hello():
        return "Hello, World!"

    # register the database commands
    from . import db

    db.init_app(app)

    # apply the blueprints to the app
    from . import auth
    from . import blog

    app.register_blueprint(auth.bp)
    app.register_blueprint(blog.bp)

    # make url_for('index') == url_for('blog.index')
    # in another app, you might define a separate main index here with
    # app.route, while giving the blog blueprint a url_prefix, but for
    # the tutorial the blog will be the main index
    app.add_url_rule("/", endpoint="index")

    return app


Filepath: githubCode\examples\tutorial\tests\conftest.py:

import os
import tempfile

import pytest

from flaskr import create_app
from flaskr.db import get_db
from flaskr.db import init_db

# read in SQL for populating test data
with open(os.path.join(os.path.dirname(__file__), "data.sql"), "rb") as f:
    _data_sql = f.read().decode("utf8")


@pytest.fixture
def app():
    """Create and configure a new app instance for each test."""
    # create a temporary file to isolate the database for each test
    db_fd, db_path = tempfile.mkstemp()
    # create the app with common test config
    app = create_app({"TESTING": True, "DATABASE": db_path})

    # create the database and load test data
    with app.app_context():
        init_db()
        get_db().executescript(_data_sql)

    yield app

    # close and remove the temporary database
    os.close(db_fd)
    os.unlink(db_path)


@pytest.fixture
def client(app):
    """A test client for the app."""
    return app.test_client()


@pytest.fixture
def runner(app):
    """A test runner for the app's Click commands."""
    return app.test_cli_runner()


class AuthActions:
    def __init__(self, client):
        self._client = client

    def login(self, username="test", password="test"):
        return self._client.post(
            "/auth/login", data={"username": username, "password": password}
        )

    def logout(self):
        return self._client.get("/auth/logout")


@pytest.fixture
def auth(client):
    return AuthActions(client)


Filepath: githubCode\examples\tutorial\tests\test_auth.py:

import pytest
from flask import g
from flask import session

from flaskr.db import get_db


def test_register(client, app):
    # test that viewing the page renders without template errors
    assert client.get("/auth/register").status_code == 200

    # test that successful registration redirects to the login page
    response = client.post("/auth/register", data={"username": "a", "password": "a"})
    assert response.headers["Location"] == "/auth/login"

    # test that the user was inserted into the database
    with app.app_context():
        assert (
            get_db().execute("SELECT * FROM user WHERE username = 'a'").fetchone()
            is not None
        )


@pytest.mark.parametrize(
    ("username", "password", "message"),
    (
        ("", "", b"Username is required."),
        ("a", "", b"Password is required."),
        ("test", "test", b"already registered"),
    ),
)
def test_register_validate_input(client, username, password, message):
    response = client.post(
        "/auth/register", data={"username": username, "password": password}
    )
    assert message in response.data


def test_login(client, auth):
    # test that viewing the page renders without template errors
    assert client.get("/auth/login").status_code == 200

    # test that successful login redirects to the index page
    response = auth.login()
    assert response.headers["Location"] == "/"

    # login request set the user_id in the session
    # check that the user is loaded from the session
    with client:
        client.get("/")
        assert session["user_id"] == 1
        assert g.user["username"] == "test"


@pytest.mark.parametrize(
    ("username", "password", "message"),
    (("a", "test", b"Incorrect username."), ("test", "a", b"Incorrect password.")),
)
def test_login_validate_input(auth, username, password, message):
    response = auth.login(username, password)
    assert message in response.data


def test_logout(client, auth):
    auth.login()

    with client:
        auth.logout()
        assert "user_id" not in session


Filepath: githubCode\examples\tutorial\tests\test_blog.py:

import pytest

from flaskr.db import get_db


def test_index(client, auth):
    response = client.get("/")
    assert b"Log In" in response.data
    assert b"Register" in response.data

    auth.login()
    response = client.get("/")
    assert b"test title" in response.data
    assert b"by test on 2018-01-01" in response.data
    assert b"test\nbody" in response.data
    assert b'href="/1/update"' in response.data


@pytest.mark.parametrize("path", ("/create", "/1/update", "/1/delete"))
def test_login_required(client, path):
    response = client.post(path)
    assert response.headers["Location"] == "/auth/login"


def test_author_required(app, client, auth):
    # change the post author to another user
    with app.app_context():
        db = get_db()
        db.execute("UPDATE post SET author_id = 2 WHERE id = 1")
        db.commit()

    auth.login()
    # current user can't modify other user's post
    assert client.post("/1/update").status_code == 403
    assert client.post("/1/delete").status_code == 403
    # current user doesn't see edit link
    assert b'href="/1/update"' not in client.get("/").data


@pytest.mark.parametrize("path", ("/2/update", "/2/delete"))
def test_exists_required(client, auth, path):
    auth.login()
    assert client.post(path).status_code == 404


def test_create(client, auth, app):
    auth.login()
    assert client.get("/create").status_code == 200
    client.post("/create", data={"title": "created", "body": ""})

    with app.app_context():
        db = get_db()
        count = db.execute("SELECT COUNT(id) FROM post").fetchone()[0]
        assert count == 2


def test_update(client, auth, app):
    auth.login()
    assert client.get("/1/update").status_code == 200
    client.post("/1/update", data={"title": "updated", "body": ""})

    with app.app_context():
        db = get_db()
        post = db.execute("SELECT * FROM post WHERE id = 1").fetchone()
        assert post["title"] == "updated"


@pytest.mark.parametrize("path", ("/create", "/1/update"))
def test_create_update_validate(client, auth, path):
    auth.login()
    response = client.post(path, data={"title": "", "body": ""})
    assert b"Title is required." in response.data


def test_delete(client, auth, app):
    auth.login()
    response = client.post("/1/delete")
    assert response.headers["Location"] == "/"

    with app.app_context():
        db = get_db()
        post = db.execute("SELECT * FROM post WHERE id = 1").fetchone()
        assert post is None


Filepath: githubCode\examples\tutorial\tests\test_db.py:

import sqlite3

import pytest

from flaskr.db import get_db


def test_get_close_db(app):
    with app.app_context():
        db = get_db()
        assert db is get_db()

    with pytest.raises(sqlite3.ProgrammingError) as e:
        db.execute("SELECT 1")

    assert "closed" in str(e.value)


def test_init_db_command(runner, monkeypatch):
    class Recorder:
        called = False

    def fake_init_db():
        Recorder.called = True

    monkeypatch.setattr("flaskr.db.init_db", fake_init_db)
    result = runner.invoke(args=["init-db"])
    assert "Initialized" in result.output
    assert Recorder.called


Filepath: githubCode\examples\tutorial\tests\test_factory.py:

from flaskr import create_app


def test_config():
    """Test create_app without passing test config."""
    assert not create_app().testing
    assert create_app({"TESTING": True}).testing


def test_hello(client):
    response = client.get("/hello")
    assert response.data == b"Hello, World!"


Filepath: githubCode\src\flask\app.py:

from __future__ import annotations

import collections.abc as cabc
import os
import sys
import typing as t
import weakref
from datetime import timedelta
from inspect import iscoroutinefunction
from itertools import chain
from types import TracebackType
from urllib.parse import quote as _url_quote

import click
from werkzeug.datastructures import Headers
from werkzeug.datastructures import ImmutableDict
from werkzeug.exceptions import BadRequestKeyError
from werkzeug.exceptions import HTTPException
from werkzeug.exceptions import InternalServerError
from werkzeug.routing import BuildError
from werkzeug.routing import MapAdapter
from werkzeug.routing import RequestRedirect
from werkzeug.routing import RoutingException
from werkzeug.routing import Rule
from werkzeug.serving import is_running_from_reloader
from werkzeug.wrappers import Response as BaseResponse

from . import cli
from . import typing as ft
from .ctx import AppContext
from .ctx import RequestContext
from .globals import _cv_app
from .globals import _cv_request
from .globals import current_app
from .globals import g
from .globals import request
from .globals import request_ctx
from .globals import session
from .helpers import get_debug_flag
from .helpers import get_flashed_messages
from .helpers import get_load_dotenv
from .helpers import send_from_directory
from .sansio.app import App
from .sansio.scaffold import _sentinel
from .sessions import SecureCookieSessionInterface
from .sessions import SessionInterface
from .signals import appcontext_tearing_down
from .signals import got_request_exception
from .signals import request_finished
from .signals import request_started
from .signals import request_tearing_down
from .templating import Environment
from .wrappers import Request
from .wrappers import Response

if t.TYPE_CHECKING:  # pragma: no cover
    from _typeshed.wsgi import StartResponse
    from _typeshed.wsgi import WSGIEnvironment

    from .testing import FlaskClient
    from .testing import FlaskCliRunner

T_shell_context_processor = t.TypeVar(
    "T_shell_context_processor", bound=ft.ShellContextProcessorCallable
)
T_teardown = t.TypeVar("T_teardown", bound=ft.TeardownCallable)
T_template_filter = t.TypeVar("T_template_filter", bound=ft.TemplateFilterCallable)
T_template_global = t.TypeVar("T_template_global", bound=ft.TemplateGlobalCallable)
T_template_test = t.TypeVar("T_template_test", bound=ft.TemplateTestCallable)


def _make_timedelta(value: timedelta | int | None) -> timedelta | None:
    if value is None or isinstance(value, timedelta):
        return value

    return timedelta(seconds=value)


class Flask(App):
    """The flask object implements a WSGI application and acts as the central
    object.  It is passed the name of the module or package of the
    application.  Once it is created it will act as a central registry for
    the view functions, the URL rules, template configuration and much more.

    The name of the package is used to resolve resources from inside the
    package or the folder the module is contained in depending on if the
    package parameter resolves to an actual python package (a folder with
    an :file:`__init__.py` file inside) or a standard module (just a ``.py`` file).

    For more information about resource loading, see :func:`open_resource`.

    Usually you create a :class:`Flask` instance in your main module or
    in the :file:`__init__.py` file of your package like this::

        from flask import Flask
        app = Flask(__name__)

    .. admonition:: About the First Parameter

        The idea of the first parameter is to give Flask an idea of what
        belongs to your application.  This name is used to find resources
        on the filesystem, can be used by extensions to improve debugging
        information and a lot more.

        So it's important what you provide there.  If you are using a single
        module, `__name__` is always the correct value.  If you however are
        using a package, it's usually recommended to hardcode the name of
        your package there.

        For example if your application is defined in :file:`yourapplication/app.py`
        you should create it with one of the two versions below::

            app = Flask('yourapplication')
            app = Flask(__name__.split('.')[0])

        Why is that?  The application will work even with `__name__`, thanks
        to how resources are looked up.  However it will make debugging more
        painful.  Certain extensions can make assumptions based on the
        import name of your application.  For example the Flask-SQLAlchemy
        extension will look for the code in your application that triggered
        an SQL query in debug mode.  If the import name is not properly set
        up, that debugging information is lost.  (For example it would only
        pick up SQL queries in `yourapplication.app` and not
        `yourapplication.views.frontend`)

    .. versionadded:: 0.7
       The `static_url_path`, `static_folder`, and `template_folder`
       parameters were added.

    .. versionadded:: 0.8
       The `instance_path` and `instance_relative_config` parameters were
       added.

    .. versionadded:: 0.11
       The `root_path` parameter was added.

    .. versionadded:: 1.0
       The ``host_matching`` and ``static_host`` parameters were added.

    .. versionadded:: 1.0
       The ``subdomain_matching`` parameter was added. Subdomain
       matching needs to be enabled manually now. Setting
       :data:`SERVER_NAME` does not implicitly enable it.

    :param import_name: the name of the application package
    :param static_url_path: can be used to specify a different path for the
                            static files on the web.  Defaults to the name
                            of the `static_folder` folder.
    :param static_folder: The folder with static files that is served at
        ``static_url_path``. Relative to the application ``root_path``
        or an absolute path. Defaults to ``'static'``.
    :param static_host: the host to use when adding the static route.
        Defaults to None. Required when using ``host_matching=True``
        with a ``static_folder`` configured.
    :param host_matching: set ``url_map.host_matching`` attribute.
        Defaults to False.
    :param subdomain_matching: consider the subdomain relative to
        :data:`SERVER_NAME` when matching routes. Defaults to False.
    :param template_folder: the folder that contains the templates that should
                            be used by the application.  Defaults to
                            ``'templates'`` folder in the root path of the
                            application.
    :param instance_path: An alternative instance path for the application.
                          By default the folder ``'instance'`` next to the
                          package or module is assumed to be the instance
                          path.
    :param instance_relative_config: if set to ``True`` relative filenames
                                     for loading the config are assumed to
                                     be relative to the instance path instead
                                     of the application root.
    :param root_path: The path to the root of the application files.
        This should only be set manually when it can't be detected
        automatically, such as for namespace packages.
    """

    default_config = ImmutableDict(
        {
            "DEBUG": None,
            "TESTING": False,
            "PROPAGATE_EXCEPTIONS": None,
            "SECRET_KEY": None,
            "PERMANENT_SESSION_LIFETIME": timedelta(days=31),
            "USE_X_SENDFILE": False,
            "SERVER_NAME": None,
            "APPLICATION_ROOT": "/",
            "SESSION_COOKIE_NAME": "session",
            "SESSION_COOKIE_DOMAIN": None,
            "SESSION_COOKIE_PATH": None,
            "SESSION_COOKIE_HTTPONLY": True,
            "SESSION_COOKIE_SECURE": False,
            "SESSION_COOKIE_SAMESITE": None,
            "SESSION_REFRESH_EACH_REQUEST": True,
            "MAX_CONTENT_LENGTH": None,
            "SEND_FILE_MAX_AGE_DEFAULT": None,
            "TRAP_BAD_REQUEST_ERRORS": None,
            "TRAP_HTTP_EXCEPTIONS": False,
            "EXPLAIN_TEMPLATE_LOADING": False,
            "PREFERRED_URL_SCHEME": "http",
            "TEMPLATES_AUTO_RELOAD": None,
            "MAX_COOKIE_SIZE": 4093,
        }
    )

    #: The class that is used for request objects.  See :class:`~flask.Request`
    #: for more information.
    request_class: type[Request] = Request

    #: The class that is used for response objects.  See
    #: :class:`~flask.Response` for more information.
    response_class: type[Response] = Response

    #: the session interface to use.  By default an instance of
    #: :class:`~flask.sessions.SecureCookieSessionInterface` is used here.
    #:
    #: .. versionadded:: 0.8
    session_interface: SessionInterface = SecureCookieSessionInterface()

    def __init__(
        self,
        import_name: str,
        static_url_path: str | None = None,
        static_folder: str | os.PathLike[str] | None = "static",
        static_host: str | None = None,
        host_matching: bool = False,
        subdomain_matching: bool = False,
        template_folder: str | os.PathLike[str] | None = "templates",
        instance_path: str | None = None,
        instance_relative_config: bool = False,
        root_path: str | None = None,
    ):
        super().__init__(
            import_name=import_name,
            static_url_path=static_url_path,
            static_folder=static_folder,
            static_host=static_host,
            host_matching=host_matching,
            subdomain_matching=subdomain_matching,
            template_folder=template_folder,
            instance_path=instance_path,
            instance_relative_config=instance_relative_config,
            root_path=root_path,
        )

        # Add a static route using the provided static_url_path, static_host,
        # and static_folder if there is a configured static_folder.
        # Note we do this without checking if static_folder exists.
        # For one, it might be created while the server is running (e.g. during
        # development). Also, Google App Engine stores static files somewhere
        if self.has_static_folder:
            assert (
                bool(static_host) == host_matching
            ), "Invalid static_host/host_matching combination"
            # Use a weakref to avoid creating a reference cycle between the app
            # and the view function (see #3761).
            self_ref = weakref.ref(self)
            self.add_url_rule(
                f"{self.static_url_path}/<path:filename>",
                endpoint="static",
                host=static_host,
                view_func=lambda **kw: self_ref().send_static_file(**kw),  # type: ignore # noqa: B950
            )

    def get_send_file_max_age(self, filename: str | None) -> int | None:
        """Used by :func:`send_file` to determine the ``max_age`` cache
        value for a given file path if it wasn't passed.

        By default, this returns :data:`SEND_FILE_MAX_AGE_DEFAULT` from
        the configuration of :data:`~flask.current_app`. This defaults
        to ``None``, which tells the browser to use conditional requests
        instead of a timed cache, which is usually preferable.

        Note this is a duplicate of the same method in the Flask
        class.

        .. versionchanged:: 2.0
            The default configuration is ``None`` instead of 12 hours.

        .. versionadded:: 0.9
        """
        value = current_app.config["SEND_FILE_MAX_AGE_DEFAULT"]

        if value is None:
            return None

        if isinstance(value, timedelta):
            return int(value.total_seconds())

        return value  # type: ignore[no-any-return]

    def send_static_file(self, filename: str) -> Response:
        """The view function used to serve files from
        :attr:`static_folder`. A route is automatically registered for
        this view at :attr:`static_url_path` if :attr:`static_folder` is
        set.

        Note this is a duplicate of the same method in the Flask
        class.

        .. versionadded:: 0.5

        """
        if not self.has_static_folder:
            raise RuntimeError("'static_folder' must be set to serve static_files.")

        # send_file only knows to call get_send_file_max_age on the app,
        # call it here so it works for blueprints too.
        max_age = self.get_send_file_max_age(filename)
        return send_from_directory(
            t.cast(str, self.static_folder), filename, max_age=max_age
        )

    def open_resource(self, resource: str, mode: str = "rb") -> t.IO[t.AnyStr]:
        """Open a resource file relative to :attr:`root_path` for
        reading.

        For example, if the file ``schema.sql`` is next to the file
        ``app.py`` where the ``Flask`` app is defined, it can be opened
        with:

        .. code-block:: python

            with app.open_resource("schema.sql") as f:
                conn.executescript(f.read())

        :param resource: Path to the resource relative to
            :attr:`root_path`.
        :param mode: Open the file in this mode. Only reading is
            supported, valid values are "r" (or "rt") and "rb".

        Note this is a duplicate of the same method in the Flask
        class.

        """
        if mode not in {"r", "rt", "rb"}:
            raise ValueError("Resources can only be opened for reading.")

        return open(os.path.join(self.root_path, resource), mode)

    def open_instance_resource(self, resource: str, mode: str = "rb") -> t.IO[t.AnyStr]:
        """Opens a resource from the application's instance folder
        (:attr:`instance_path`).  Otherwise works like
        :meth:`open_resource`.  Instance resources can also be opened for
        writing.

        :param resource: the name of the resource.  To access resources within
                         subfolders use forward slashes as separator.
        :param mode: resource file opening mode, default is 'rb'.
        """
        return open(os.path.join(self.instance_path, resource), mode)

    def create_jinja_environment(self) -> Environment:
        """Create the Jinja environment based on :attr:`jinja_options`
        and the various Jinja-related methods of the app. Changing
        :attr:`jinja_options` after this will have no effect. Also adds
        Flask-related globals and filters to the environment.

        .. versionchanged:: 0.11
           ``Environment.auto_reload`` set in accordance with
           ``TEMPLATES_AUTO_RELOAD`` configuration option.

        .. versionadded:: 0.5
        """
        options = dict(self.jinja_options)

        if "autoescape" not in options:
            options["autoescape"] = self.select_jinja_autoescape

        if "auto_reload" not in options:
            auto_reload = self.config["TEMPLATES_AUTO_RELOAD"]

            if auto_reload is None:
                auto_reload = self.debug

            options["auto_reload"] = auto_reload

        rv = self.jinja_environment(self, **options)
        rv.globals.update(
            url_for=self.url_for,
            get_flashed_messages=get_flashed_messages,
            config=self.config,
            # request, session and g are normally added with the
            # context processor for efficiency reasons but for imported
            # templates we also want the proxies in there.
            request=request,
            session=session,
            g=g,
        )
        rv.policies["json.dumps_function"] = self.json.dumps
        return rv

    def create_url_adapter(self, request: Request | None) -> MapAdapter | None:
        """Creates a URL adapter for the given request. The URL adapter
        is created at a point where the request context is not yet set
        up so the request is passed explicitly.

        .. versionadded:: 0.6

        .. versionchanged:: 0.9
           This can now also be called without a request object when the
           URL adapter is created for the application context.

        .. versionchanged:: 1.0
            :data:`SERVER_NAME` no longer implicitly enables subdomain
            matching. Use :attr:`subdomain_matching` instead.
        """
        if request is not None:
            # If subdomain matching is disabled (the default), use the
            # default subdomain in all cases. This should be the default
            # in Werkzeug but it currently does not have that feature.
            if not self.subdomain_matching:
                subdomain = self.url_map.default_subdomain or None
            else:
                subdomain = None

            return self.url_map.bind_to_environ(
                request.environ,
                server_name=self.config["SERVER_NAME"],
                subdomain=subdomain,
            )
        # We need at the very least the server name to be set for this
        # to work.
        if self.config["SERVER_NAME"] is not None:
            return self.url_map.bind(
                self.config["SERVER_NAME"],
                script_name=self.config["APPLICATION_ROOT"],
                url_scheme=self.config["PREFERRED_URL_SCHEME"],
            )

        return None

    def raise_routing_exception(self, request: Request) -> t.NoReturn:
        """Intercept routing exceptions and possibly do something else.

        In debug mode, intercept a routing redirect and replace it with
        an error if the body will be discarded.

        With modern Werkzeug this shouldn't occur, since it now uses a
        308 status which tells the browser to resend the method and
        body.

        .. versionchanged:: 2.1
            Don't intercept 307 and 308 redirects.

        :meta private:
        :internal:
        """
        if (
            not self.debug
            or not isinstance(request.routing_exception, RequestRedirect)
            or request.routing_exception.code in {307, 308}
            or request.method in {"GET", "HEAD", "OPTIONS"}
        ):
            raise request.routing_exception  # type: ignore[misc]

        from .debughelpers import FormDataRoutingRedirect

        raise FormDataRoutingRedirect(request)

    def update_template_context(self, context: dict[str, t.Any]) -> None:
        """Update the template context with some commonly used variables.
        This injects request, session, config and g into the template
        context as well as everything template context processors want
        to inject.  Note that the as of Flask 0.6, the original values
        in the context will not be overridden if a context processor
        decides to return a value with the same key.

        :param context: the context as a dictionary that is updated in place
                        to add extra variables.
        """
        names: t.Iterable[str | None] = (None,)

        # A template may be rendered outside a request context.
        if request:
            names = chain(names, reversed(request.blueprints))

        # The values passed to render_template take precedence. Keep a
        # copy to re-apply after all context functions.
        orig_ctx = context.copy()

        for name in names:
            if name in self.template_context_processors:
                for func in self.template_context_processors[name]:
                    context.update(self.ensure_sync(func)())

        context.update(orig_ctx)

    def make_shell_context(self) -> dict[str, t.Any]:
        """Returns the shell context for an interactive shell for this
        application.  This runs all the registered shell context
        processors.

        .. versionadded:: 0.11
        """
        rv = {"app": self, "g": g}
        for processor in self.shell_context_processors:
            rv.update(processor())
        return rv

    def run(
        self,
        host: str | None = None,
        port: int | None = None,
        debug: bool | None = None,
        load_dotenv: bool = True,
        **options: t.Any,
    ) -> None:
        """Runs the application on a local development server.

        Do not use ``run()`` in a production setting. It is not intended to
        meet security and performance requirements for a production server.
        Instead, see :doc:`/deploying/index` for WSGI server recommendations.

        If the :attr:`debug` flag is set the server will automatically reload
        for code changes and show a debugger in case an exception happened.

        If you want to run the application in debug mode, but disable the
        code execution on the interactive debugger, you can pass
        ``use_evalex=False`` as parameter.  This will keep the debugger's
        traceback screen active, but disable code execution.

        It is not recommended to use this function for development with
        automatic reloading as this is badly supported.  Instead you should
        be using the :command:`flask` command line script's ``run`` support.

        .. admonition:: Keep in Mind

           Flask will suppress any server error with a generic error page
           unless it is in debug mode.  As such to enable just the
           interactive debugger without the code reloading, you have to
           invoke :meth:`run` with ``debug=True`` and ``use_reloader=False``.
           Setting ``use_debugger`` to ``True`` without being in debug mode
           won't catch any exceptions because there won't be any to
           catch.

        :param host: the hostname to listen on. Set this to ``'0.0.0.0'`` to
            have the server available externally as well. Defaults to
            ``'127.0.0.1'`` or the host in the ``SERVER_NAME`` config variable
            if present.
        :param port: the port of the webserver. Defaults to ``5000`` or the
            port defined in the ``SERVER_NAME`` config variable if present.
        :param debug: if given, enable or disable debug mode. See
            :attr:`debug`.
        :param load_dotenv: Load the nearest :file:`.env` and :file:`.flaskenv`
            files to set environment variables. Will also change the working
            directory to the directory containing the first file found.
        :param options: the options to be forwarded to the underlying Werkzeug
            server. See :func:`werkzeug.serving.run_simple` for more
            information.

        .. versionchanged:: 1.0
            If installed, python-dotenv will be used to load environment
            variables from :file:`.env` and :file:`.flaskenv` files.

            The :envvar:`FLASK_DEBUG` environment variable will override :attr:`debug`.

            Threaded mode is enabled by default.

        .. versionchanged:: 0.10
            The default port is now picked from the ``SERVER_NAME``
            variable.
        """
        # Ignore this call so that it doesn't start another server if
        # the 'flask run' command is used.
        if os.environ.get("FLASK_RUN_FROM_CLI") == "true":
            if not is_running_from_reloader():
                click.secho(
                    " * Ignoring a call to 'app.run()' that would block"
                    " the current 'flask' CLI command.\n"
                    "   Only call 'app.run()' in an 'if __name__ =="
                    ' "__main__"\' guard.',
                    fg="red",
                )

            return

        if get_load_dotenv(load_dotenv):
            cli.load_dotenv()

            # if set, env var overrides existing value
            if "FLASK_DEBUG" in os.environ:
                self.debug = get_debug_flag()

        # debug passed to method overrides all other sources
        if debug is not None:
            self.debug = bool(debug)

        server_name = self.config.get("SERVER_NAME")
        sn_host = sn_port = None

        if server_name:
            sn_host, _, sn_port = server_name.partition(":")

        if not host:
            if sn_host:
                host = sn_host
            else:
                host = "127.0.0.1"

        if port or port == 0:
            port = int(port)
        elif sn_port:
            port = int(sn_port)
        else:
            port = 5000

        options.setdefault("use_reloader", self.debug)
        options.setdefault("use_debugger", self.debug)
        options.setdefault("threaded", True)

        cli.show_server_banner(self.debug, self.name)

        from werkzeug.serving import run_simple

        try:
            run_simple(t.cast(str, host), port, self, **options)
        finally:
            # reset the first request information if the development server
            # reset normally.  This makes it possible to restart the server
            # without reloader and that stuff from an interactive shell.
            self._got_first_request = False

    def test_client(self, use_cookies: bool = True, **kwargs: t.Any) -> FlaskClient:
        """Creates a test client for this application.  For information
        about unit testing head over to :doc:`/testing`.

        Note that if you are testing for assertions or exceptions in your
        application code, you must set ``app.testing = True`` in order for the
        exceptions to propagate to the test client.  Otherwise, the exception
        will be handled by the application (not visible to the test client) and
        the only indication of an AssertionError or other exception will be a
        500 status code response to the test client.  See the :attr:`testing`
        attribute.  For example::

            app.testing = True
            client = app.test_client()

        The test client can be used in a ``with`` block to defer the closing down
        of the context until the end of the ``with`` block.  This is useful if
        you want to access the context locals for testing::

            with app.test_client() as c:
                rv = c.get('/?vodka=42')
                assert request.args['vodka'] == '42'

        Additionally, you may pass optional keyword arguments that will then
        be passed to the application's :attr:`test_client_class` constructor.
        For example::

            from flask.testing import FlaskClient

            class CustomClient(FlaskClient):
                def __init__(self, *args, **kwargs):
                    self._authentication = kwargs.pop("authentication")
                    super(CustomClient,self).__init__( *args, **kwargs)

            app.test_client_class = CustomClient
            client = app.test_client(authentication='Basic ....')

        See :class:`~flask.testing.FlaskClient` for more information.

        .. versionchanged:: 0.4
           added support for ``with`` block usage for the client.

        .. versionadded:: 0.7
           The `use_cookies` parameter was added as well as the ability
           to override the client to be used by setting the
           :attr:`test_client_class` attribute.

        .. versionchanged:: 0.11
           Added `**kwargs` to support passing additional keyword arguments to
           the constructor of :attr:`test_client_class`.
        """
        cls = self.test_client_class
        if cls is None:
            from .testing import FlaskClient as cls
        return cls(  # type: ignore
            self, self.response_class, use_cookies=use_cookies, **kwargs
        )

    def test_cli_runner(self, **kwargs: t.Any) -> FlaskCliRunner:
        """Create a CLI runner for testing CLI commands.
        See :ref:`testing-cli`.

        Returns an instance of :attr:`test_cli_runner_class`, by default
        :class:`~flask.testing.FlaskCliRunner`. The Flask app object is
        passed as the first argument.

        .. versionadded:: 1.0
        """
        cls = self.test_cli_runner_class

        if cls is None:
            from .testing import FlaskCliRunner as cls

        return cls(self, **kwargs)  # type: ignore

    def handle_http_exception(
        self, e: HTTPException
    ) -> HTTPException | ft.ResponseReturnValue:
        """Handles an HTTP exception.  By default this will invoke the
        registered error handlers and fall back to returning the
        exception as response.

        .. versionchanged:: 1.0.3
            ``RoutingException``, used internally for actions such as
             slash redirects during routing, is not passed to error
             handlers.

        .. versionchanged:: 1.0
            Exceptions are looked up by code *and* by MRO, so
            ``HTTPException`` subclasses can be handled with a catch-all
            handler for the base ``HTTPException``.

        .. versionadded:: 0.3
        """
        # Proxy exceptions don't have error codes.  We want to always return
        # those unchanged as errors
        if e.code is None:
            return e

        # RoutingExceptions are used internally to trigger routing
        # actions, such as slash redirects raising RequestRedirect. They
        # are not raised or handled in user code.
        if isinstance(e, RoutingException):
            return e

        handler = self._find_error_handler(e, request.blueprints)
        if handler is None:
            return e
        return self.ensure_sync(handler)(e)  # type: ignore[no-any-return]

    def handle_user_exception(
        self, e: Exception
    ) -> HTTPException | ft.ResponseReturnValue:
        """This method is called whenever an exception occurs that
        should be handled. A special case is :class:`~werkzeug
        .exceptions.HTTPException` which is forwarded to the
        :meth:`handle_http_exception` method. This function will either
        return a response value or reraise the exception with the same
        traceback.

        .. versionchanged:: 1.0
            Key errors raised from request data like ``form`` show the
            bad key in debug mode rather than a generic bad request
            message.

        .. versionadded:: 0.7
        """
        if isinstance(e, BadRequestKeyError) and (
            self.debug or self.config["TRAP_BAD_REQUEST_ERRORS"]
        ):
            e.show_exception = True

        if isinstance(e, HTTPException) and not self.trap_http_exception(e):
            return self.handle_http_exception(e)

        handler = self._find_error_handler(e, request.blueprints)

        if handler is None:
            raise

        return self.ensure_sync(handler)(e)  # type: ignore[no-any-return]

    def handle_exception(self, e: Exception) -> Response:
        """Handle an exception that did not have an error handler
        associated with it, or that was raised from an error handler.
        This always causes a 500 ``InternalServerError``.

        Always sends the :data:`got_request_exception` signal.

        If :data:`PROPAGATE_EXCEPTIONS` is ``True``, such as in debug
        mode, the error will be re-raised so that the debugger can
        display it. Otherwise, the original exception is logged, and
        an :exc:`~werkzeug.exceptions.InternalServerError` is returned.

        If an error handler is registered for ``InternalServerError`` or
        ``500``, it will be used. For consistency, the handler will
        always receive the ``InternalServerError``. The original
        unhandled exception is available as ``e.original_exception``.

        .. versionchanged:: 1.1.0
            Always passes the ``InternalServerError`` instance to the
            handler, setting ``original_exception`` to the unhandled
            error.

        .. versionchanged:: 1.1.0
            ``after_request`` functions and other finalization is done
            even for the default 500 response when there is no handler.

        .. versionadded:: 0.3
        """
        exc_info = sys.exc_info()
        got_request_exception.send(self, _async_wrapper=self.ensure_sync, exception=e)
        propagate = self.config["PROPAGATE_EXCEPTIONS"]

        if propagate is None:
            propagate = self.testing or self.debug

        if propagate:
            # Re-raise if called with an active exception, otherwise
            # raise the passed in exception.
            if exc_info[1] is e:
                raise

            raise e

        self.log_exception(exc_info)
        server_error: InternalServerError | ft.ResponseReturnValue
        server_error = InternalServerError(original_exception=e)
        handler = self._find_error_handler(server_error, request.blueprints)

        if handler is not None:
            server_error = self.ensure_sync(handler)(server_error)

        return self.finalize_request(server_error, from_error_handler=True)

    def log_exception(
        self,
        exc_info: (tuple[type, BaseException, TracebackType] | tuple[None, None, None]),
    ) -> None:
        """Logs an exception.  This is called by :meth:`handle_exception`
        if debugging is disabled and right before the handler is called.
        The default implementation logs the exception as error on the
        :attr:`logger`.

        .. versionadded:: 0.8
        """
        self.logger.error(
            f"Exception on {request.path} [{request.method}]", exc_info=exc_info
        )

    def dispatch_request(self) -> ft.ResponseReturnValue:
        """Does the request dispatching.  Matches the URL and returns the
        return value of the view or error handler.  This does not have to
        be a response object.  In order to convert the return value to a
        proper response object, call :func:`make_response`.

        .. versionchanged:: 0.7
           This no longer does the exception handling, this code was
           moved to the new :meth:`full_dispatch_request`.
        """
        req = request_ctx.request
        if req.routing_exception is not None:
            self.raise_routing_exception(req)
        rule: Rule = req.url_rule  # type: ignore[assignment]
        # if we provide automatic options for this URL and the
        # request came with the OPTIONS method, reply automatically
        if (
            getattr(rule, "provide_automatic_options", False)
            and req.method == "OPTIONS"
        ):
            return self.make_default_options_response()
        # otherwise dispatch to the handler for that endpoint
        view_args: dict[str, t.Any] = req.view_args  # type: ignore[assignment]
        return self.ensure_sync(self.view_functions[rule.endpoint])(**view_args)  # type: ignore[no-any-return]

    def full_dispatch_request(self) -> Response:
        """Dispatches the request and on top of that performs request
        pre and postprocessing as well as HTTP exception catching and
        error handling.

        .. versionadded:: 0.7
        """
        self._got_first_request = True

        try:
            request_started.send(self, _async_wrapper=self.ensure_sync)
            rv = self.preprocess_request()
            if rv is None:
                rv = self.dispatch_request()
        except Exception as e:
            rv = self.handle_user_exception(e)
        return self.finalize_request(rv)

    def finalize_request(
        self,
        rv: ft.ResponseReturnValue | HTTPException,
        from_error_handler: bool = False,
    ) -> Response:
        """Given the return value from a view function this finalizes
        the request by converting it into a response and invoking the
        postprocessing functions.  This is invoked for both normal
        request dispatching as well as error handlers.

        Because this means that it might be called as a result of a
        failure a special safe mode is available which can be enabled
        with the `from_error_handler` flag.  If enabled, failures in
        response processing will be logged and otherwise ignored.

        :internal:
        """
        response = self.make_response(rv)
        try:
            response = self.process_response(response)
            request_finished.send(
                self, _async_wrapper=self.ensure_sync, response=response
            )
        except Exception:
            if not from_error_handler:
                raise
            self.logger.exception(
                "Request finalizing failed with an error while handling an error"
            )
        return response

    def make_default_options_response(self) -> Response:
        """This method is called to create the default ``OPTIONS`` response.
        This can be changed through subclassing to change the default
        behavior of ``OPTIONS`` responses.

        .. versionadded:: 0.7
        """
        adapter = request_ctx.url_adapter
        methods = adapter.allowed_methods()  # type: ignore[union-attr]
        rv = self.response_class()
        rv.allow.update(methods)
        return rv

    def ensure_sync(self, func: t.Callable[..., t.Any]) -> t.Callable[..., t.Any]:
        """Ensure that the function is synchronous for WSGI workers.
        Plain ``def`` functions are returned as-is. ``async def``
        functions are wrapped to run and wait for the response.

        Override this method to change how the app runs async views.

        .. versionadded:: 2.0
        """
        if iscoroutinefunction(func):
            return self.async_to_sync(func)

        return func

    def async_to_sync(
        self, func: t.Callable[..., t.Coroutine[t.Any, t.Any, t.Any]]
    ) -> t.Callable[..., t.Any]:
        """Return a sync function that will run the coroutine function.

        .. code-block:: python

            result = app.async_to_sync(func)(*args, **kwargs)

        Override this method to change how the app converts async code
        to be synchronously callable.

        .. versionadded:: 2.0
        """
        try:
            from asgiref.sync import async_to_sync as asgiref_async_to_sync
        except ImportError:
            raise RuntimeError(
                "Install Flask with the 'async' extra in order to use async views."
            ) from None

        return asgiref_async_to_sync(func)

    def url_for(
        self,
        /,
        endpoint: str,
        *,
        _anchor: str | None = None,
        _method: str | None = None,
        _scheme: str | None = None,
        _external: bool | None = None,
        **values: t.Any,
    ) -> str:
        """Generate a URL to the given endpoint with the given values.

        This is called by :func:`flask.url_for`, and can be called
        directly as well.

        An *endpoint* is the name of a URL rule, usually added with
        :meth:`@app.route() <route>`, and usually the same name as the
        view function. A route defined in a :class:`~flask.Blueprint`
        will prepend the blueprint's name separated by a ``.`` to the
        endpoint.

        In some cases, such as email messages, you want URLs to include
        the scheme and domain, like ``https://example.com/hello``. When
        not in an active request, URLs will be external by default, but
        this requires setting :data:`SERVER_NAME` so Flask knows what
        domain to use. :data:`APPLICATION_ROOT` and
        :data:`PREFERRED_URL_SCHEME` should also be configured as
        needed. This config is only used when not in an active request.

        Functions can be decorated with :meth:`url_defaults` to modify
        keyword arguments before the URL is built.

        If building fails for some reason, such as an unknown endpoint
        or incorrect values, the app's :meth:`handle_url_build_error`
        method is called. If that returns a string, that is returned,
        otherwise a :exc:`~werkzeug.routing.BuildError` is raised.

        :param endpoint: The endpoint name associated with the URL to
            generate. If this starts with a ``.``, the current blueprint
            name (if any) will be used.
        :param _anchor: If given, append this as ``#anchor`` to the URL.
        :param _method: If given, generate the URL associated with this
            method for the endpoint.
        :param _scheme: If given, the URL will have this scheme if it
            is external.
        :param _external: If given, prefer the URL to be internal
            (False) or require it to be external (True). External URLs
            include the scheme and domain. When not in an active
            request, URLs are external by default.
        :param values: Values to use for the variable parts of the URL
            rule. Unknown keys are appended as query string arguments,
            like ``?a=b&c=d``.

        .. versionadded:: 2.2
            Moved from ``flask.url_for``, which calls this method.
        """
        req_ctx = _cv_request.get(None)

        if req_ctx is not None:
            url_adapter = req_ctx.url_adapter
            blueprint_name = req_ctx.request.blueprint

            # If the endpoint starts with "." and the request matches a
            # blueprint, the endpoint is relative to the blueprint.
            if endpoint[:1] == ".":
                if blueprint_name is not None:
                    endpoint = f"{blueprint_name}{endpoint}"
                else:
                    endpoint = endpoint[1:]

            # When in a request, generate a URL without scheme and
            # domain by default, unless a scheme is given.
            if _external is None:
                _external = _scheme is not None
        else:
            app_ctx = _cv_app.get(None)

            # If called by helpers.url_for, an app context is active,
            # use its url_adapter. Otherwise, app.url_for was called
            # directly, build an adapter.
            if app_ctx is not None:
                url_adapter = app_ctx.url_adapter
            else:
                url_adapter = self.create_url_adapter(None)

            if url_adapter is None:
                raise RuntimeError(
                    "Unable to build URLs outside an active request"
                    " without 'SERVER_NAME' configured. Also configure"
                    " 'APPLICATION_ROOT' and 'PREFERRED_URL_SCHEME' as"
                    " needed."
                )

            # When outside a request, generate a URL with scheme and
            # domain by default.
            if _external is None:
                _external = True

        # It is an error to set _scheme when _external=False, in order
        # to avoid accidental insecure URLs.
        if _scheme is not None and not _external:
            raise ValueError("When specifying '_scheme', '_external' must be True.")

        self.inject_url_defaults(endpoint, values)

        try:
            rv = url_adapter.build(  # type: ignore[union-attr]
                endpoint,
                values,
                method=_method,
                url_scheme=_scheme,
                force_external=_external,
            )
        except BuildError as error:
            values.update(
                _anchor=_anchor, _method=_method, _scheme=_scheme, _external=_external
            )
            return self.handle_url_build_error(error, endpoint, values)

        if _anchor is not None:
            _anchor = _url_quote(_anchor, safe="%!#$&'()*+,/:;=?@")
            rv = f"{rv}#{_anchor}"

        return rv

    def make_response(self, rv: ft.ResponseReturnValue) -> Response:
        """Convert the return value from a view function to an instance of
        :attr:`response_class`.

        :param rv: the return value from the view function. The view function
            must return a response. Returning ``None``, or the view ending
            without returning, is not allowed. The following types are allowed
            for ``view_rv``:

            ``str``
                A response object is created with the string encoded to UTF-8
                as the body.

            ``bytes``
                A response object is created with the bytes as the body.

            ``dict``
                A dictionary that will be jsonify'd before being returned.

            ``list``
                A list that will be jsonify'd before being returned.

            ``generator`` or ``iterator``
                A generator that returns ``str`` or ``bytes`` to be
                streamed as the response.

            ``tuple``
                Either ``(body, status, headers)``, ``(body, status)``, or
                ``(body, headers)``, where ``body`` is any of the other types
                allowed here, ``status`` is a string or an integer, and
                ``headers`` is a dictionary or a list of ``(key, value)``
                tuples. If ``body`` is a :attr:`response_class` instance,
                ``status`` overwrites the exiting value and ``headers`` are
                extended.

            :attr:`response_class`
                The object is returned unchanged.

            other :class:`~werkzeug.wrappers.Response` class
                The object is coerced to :attr:`response_class`.

            :func:`callable`
                The function is called as a WSGI application. The result is
                used to create a response object.

        .. versionchanged:: 2.2
            A generator will be converted to a streaming response.
            A list will be converted to a JSON response.

        .. versionchanged:: 1.1
            A dict will be converted to a JSON response.

        .. versionchanged:: 0.9
           Previously a tuple was interpreted as the arguments for the
           response object.
        """

        status = headers = None

        # unpack tuple returns
        if isinstance(rv, tuple):
            len_rv = len(rv)

            # a 3-tuple is unpacked directly
            if len_rv == 3:
                rv, status, headers = rv  # type: ignore[misc]
            # decide if a 2-tuple has status or headers
            elif len_rv == 2:
                if isinstance(rv[1], (Headers, dict, tuple, list)):
                    rv, headers = rv
                else:
                    rv, status = rv  # type: ignore[assignment,misc]
            # other sized tuples are not allowed
            else:
                raise TypeError(
                    "The view function did not return a valid response tuple."
                    " The tuple must have the form (body, status, headers),"
                    " (body, status), or (body, headers)."
                )

        # the body must not be None
        if rv is None:
            raise TypeError(
                f"The view function for {request.endpoint!r} did not"
                " return a valid response. The function either returned"
                " None or ended without a return statement."
            )

        # make sure the body is an instance of the response class
        if not isinstance(rv, self.response_class):
            if isinstance(rv, (str, bytes, bytearray)) or isinstance(rv, cabc.Iterator):
                # let the response class set the status and headers instead of
                # waiting to do it manually, so that the class can handle any
                # special logic
                rv = self.response_class(
                    rv,
                    status=status,
                    headers=headers,  # type: ignore[arg-type]
                )
                status = headers = None
            elif isinstance(rv, (dict, list)):
                rv = self.json.response(rv)
            elif isinstance(rv, BaseResponse) or callable(rv):
                # evaluate a WSGI callable, or coerce a different response
                # class to the correct type
                try:
                    rv = self.response_class.force_type(
                        rv,  # type: ignore[arg-type]
                        request.environ,
                    )
                except TypeError as e:
                    raise TypeError(
                        f"{e}\nThe view function did not return a valid"
                        " response. The return type must be a string,"
                        " dict, list, tuple with headers or status,"
                        " Response instance, or WSGI callable, but it"
                        f" was a {type(rv).__name__}."
                    ).with_traceback(sys.exc_info()[2]) from None
            else:
                raise TypeError(
                    "The view function did not return a valid"
                    " response. The return type must be a string,"
                    " dict, list, tuple with headers or status,"
                    " Response instance, or WSGI callable, but it was a"
                    f" {type(rv).__name__}."
                )

        rv = t.cast(Response, rv)
        # prefer the status if it was provided
        if status is not None:
            if isinstance(status, (str, bytes, bytearray)):
                rv.status = status
            else:
                rv.status_code = status

        # extend existing headers with provided headers
        if headers:
            rv.headers.update(headers)  # type: ignore[arg-type]

        return rv

    def preprocess_request(self) -> ft.ResponseReturnValue | None:
        """Called before the request is dispatched. Calls
        :attr:`url_value_preprocessors` registered with the app and the
        current blueprint (if any). Then calls :attr:`before_request_funcs`
        registered with the app and the blueprint.

        If any :meth:`before_request` handler returns a non-None value, the
        value is handled as if it was the return value from the view, and
        further request handling is stopped.
        """
        names = (None, *reversed(request.blueprints))

        for name in names:
            if name in self.url_value_preprocessors:
                for url_func in self.url_value_preprocessors[name]:
                    url_func(request.endpoint, request.view_args)

        for name in names:
            if name in self.before_request_funcs:
                for before_func in self.before_request_funcs[name]:
                    rv = self.ensure_sync(before_func)()

                    if rv is not None:
                        return rv  # type: ignore[no-any-return]

        return None

    def process_response(self, response: Response) -> Response:
        """Can be overridden in order to modify the response object
        before it's sent to the WSGI server.  By default this will
        call all the :meth:`after_request` decorated functions.

        .. versionchanged:: 0.5
           As of Flask 0.5 the functions registered for after request
           execution are called in reverse order of registration.

        :param response: a :attr:`response_class` object.
        :return: a new response object or the same, has to be an
                 instance of :attr:`response_class`.
        """
        ctx = request_ctx._get_current_object()  # type: ignore[attr-defined]

        for func in ctx._after_request_functions:
            response = self.ensure_sync(func)(response)

        for name in chain(request.blueprints, (None,)):
            if name in self.after_request_funcs:
                for func in reversed(self.after_request_funcs[name]):
                    response = self.ensure_sync(func)(response)

        if not self.session_interface.is_null_session(ctx.session):
            self.session_interface.save_session(self, ctx.session, response)

        return response

    def do_teardown_request(
        self,
        exc: BaseException | None = _sentinel,  # type: ignore[assignment]
    ) -> None:
        """Called after the request is dispatched and the response is
        returned, right before the request context is popped.

        This calls all functions decorated with
        :meth:`teardown_request`, and :meth:`Blueprint.teardown_request`
        if a blueprint handled the request. Finally, the
        :data:`request_tearing_down` signal is sent.

        This is called by
        :meth:`RequestContext.pop() <flask.ctx.RequestContext.pop>`,
        which may be delayed during testing to maintain access to
        resources.

        :param exc: An unhandled exception raised while dispatching the
            request. Detected from the current exception information if
            not passed. Passed to each teardown function.

        .. versionchanged:: 0.9
            Added the ``exc`` argument.
        """
        if exc is _sentinel:
            exc = sys.exc_info()[1]

        for name in chain(request.blueprints, (None,)):
            if name in self.teardown_request_funcs:
                for func in reversed(self.teardown_request_funcs[name]):
                    self.ensure_sync(func)(exc)

        request_tearing_down.send(self, _async_wrapper=self.ensure_sync, exc=exc)

    def do_teardown_appcontext(
        self,
        exc: BaseException | None = _sentinel,  # type: ignore[assignment]
    ) -> None:
        """Called right before the application context is popped.

        When handling a request, the application context is popped
        after the request context. See :meth:`do_teardown_request`.

        This calls all functions decorated with
        :meth:`teardown_appcontext`. Then the
        :data:`appcontext_tearing_down` signal is sent.

        This is called by
        :meth:`AppContext.pop() <flask.ctx.AppContext.pop>`.

        .. versionadded:: 0.9
        """
        if exc is _sentinel:
            exc = sys.exc_info()[1]

        for func in reversed(self.teardown_appcontext_funcs):
            self.ensure_sync(func)(exc)

        appcontext_tearing_down.send(self, _async_wrapper=self.ensure_sync, exc=exc)

    def app_context(self) -> AppContext:
        """Create an :class:`~flask.ctx.AppContext`. Use as a ``with``
        block to push the context, which will make :data:`current_app`
        point at this application.

        An application context is automatically pushed by
        :meth:`RequestContext.push() <flask.ctx.RequestContext.push>`
        when handling a request, and when running a CLI command. Use
        this to manually create a context outside of these situations.

        ::

            with app.app_context():
                init_db()

        See :doc:`/appcontext`.

        .. versionadded:: 0.9
        """
        return AppContext(self)

    def request_context(self, environ: WSGIEnvironment) -> RequestContext:
        """Create a :class:`~flask.ctx.RequestContext` representing a
        WSGI environment. Use a ``with`` block to push the context,
        which will make :data:`request` point at this request.

        See :doc:`/reqcontext`.

        Typically you should not call this from your own code. A request
        context is automatically pushed by the :meth:`wsgi_app` when
        handling a request. Use :meth:`test_request_context` to create
        an environment and context instead of this method.

        :param environ: a WSGI environment
        """
        return RequestContext(self, environ)

    def test_request_context(self, *args: t.Any, **kwargs: t.Any) -> RequestContext:
        """Create a :class:`~flask.ctx.RequestContext` for a WSGI
        environment created from the given values. This is mostly useful
        during testing, where you may want to run a function that uses
        request data without dispatching a full request.

        See :doc:`/reqcontext`.

        Use a ``with`` block to push the context, which will make
        :data:`request` point at the request for the created
        environment. ::

            with app.test_request_context(...):
                generate_report()

        When using the shell, it may be easier to push and pop the
        context manually to avoid indentation. ::

            ctx = app.test_request_context(...)
            ctx.push()
            ...
            ctx.pop()

        Takes the same arguments as Werkzeug's
        :class:`~werkzeug.test.EnvironBuilder`, with some defaults from
        the application. See the linked Werkzeug docs for most of the
        available arguments. Flask-specific behavior is listed here.

        :param path: URL path being requested.
        :param base_url: Base URL where the app is being served, which
            ``path`` is relative to. If not given, built from
            :data:`PREFERRED_URL_SCHEME`, ``subdomain``,
            :data:`SERVER_NAME`, and :data:`APPLICATION_ROOT`.
        :param subdomain: Subdomain name to append to
            :data:`SERVER_NAME`.
        :param url_scheme: Scheme to use instead of
            :data:`PREFERRED_URL_SCHEME`.
        :param data: The request body, either as a string or a dict of
            form keys and values.
        :param json: If given, this is serialized as JSON and passed as
            ``data``. Also defaults ``content_type`` to
            ``application/json``.
        :param args: other positional arguments passed to
            :class:`~werkzeug.test.EnvironBuilder`.
        :param kwargs: other keyword arguments passed to
            :class:`~werkzeug.test.EnvironBuilder`.
        """
        from .testing import EnvironBuilder

        builder = EnvironBuilder(self, *args, **kwargs)

        try:
            return self.request_context(builder.get_environ())
        finally:
            builder.close()

    def wsgi_app(
        self, environ: WSGIEnvironment, start_response: StartResponse
    ) -> cabc.Iterable[bytes]:
        """The actual WSGI application. This is not implemented in
        :meth:`__call__` so that middlewares can be applied without
        losing a reference to the app object. Instead of doing this::

            app = MyMiddleware(app)

        It's a better idea to do this instead::

            app.wsgi_app = MyMiddleware(app.wsgi_app)

        Then you still have the original application object around and
        can continue to call methods on it.

        .. versionchanged:: 0.7
            Teardown events for the request and app contexts are called
            even if an unhandled error occurs. Other events may not be
            called depending on when an error occurs during dispatch.
            See :ref:`callbacks-and-errors`.

        :param environ: A WSGI environment.
        :param start_response: A callable accepting a status code,
            a list of headers, and an optional exception context to
            start the response.
        """
        ctx = self.request_context(environ)
        error: BaseException | None = None
        try:
            try:
                ctx.push()
                response = self.full_dispatch_request()
            except Exception as e:
                error = e
                response = self.handle_exception(e)
            except:  # noqa: B001
                error = sys.exc_info()[1]
                raise
            return response(environ, start_response)
        finally:
            if "werkzeug.debug.preserve_context" in environ:
                environ["werkzeug.debug.preserve_context"](_cv_app.get())
                environ["werkzeug.debug.preserve_context"](_cv_request.get())

            if error is not None and self.should_ignore_error(error):
                error = None

            ctx.pop(error)

    def __call__(
        self, environ: WSGIEnvironment, start_response: StartResponse
    ) -> cabc.Iterable[bytes]:
        """The WSGI server calls the Flask application object as the
        WSGI application. This calls :meth:`wsgi_app`, which can be
        wrapped to apply middleware.
        """
        return self.wsgi_app(environ, start_response)


Filepath: githubCode\src\flask\blueprints.py:

from __future__ import annotations

import os
import typing as t
from datetime import timedelta

from .globals import current_app
from .helpers import send_from_directory
from .sansio.blueprints import Blueprint as SansioBlueprint
from .sansio.blueprints import BlueprintSetupState as BlueprintSetupState  # noqa

if t.TYPE_CHECKING:  # pragma: no cover
    from .wrappers import Response


class Blueprint(SansioBlueprint):
    def get_send_file_max_age(self, filename: str | None) -> int | None:
        """Used by :func:`send_file` to determine the ``max_age`` cache
        value for a given file path if it wasn't passed.

        By default, this returns :data:`SEND_FILE_MAX_AGE_DEFAULT` from
        the configuration of :data:`~flask.current_app`. This defaults
        to ``None``, which tells the browser to use conditional requests
        instead of a timed cache, which is usually preferable.

        Note this is a duplicate of the same method in the Flask
        class.

        .. versionchanged:: 2.0
            The default configuration is ``None`` instead of 12 hours.

        .. versionadded:: 0.9
        """
        value = current_app.config["SEND_FILE_MAX_AGE_DEFAULT"]

        if value is None:
            return None

        if isinstance(value, timedelta):
            return int(value.total_seconds())

        return value  # type: ignore[no-any-return]

    def send_static_file(self, filename: str) -> Response:
        """The view function used to serve files from
        :attr:`static_folder`. A route is automatically registered for
        this view at :attr:`static_url_path` if :attr:`static_folder` is
        set.

        Note this is a duplicate of the same method in the Flask
        class.

        .. versionadded:: 0.5

        """
        if not self.has_static_folder:
            raise RuntimeError("'static_folder' must be set to serve static_files.")

        # send_file only knows to call get_send_file_max_age on the app,
        # call it here so it works for blueprints too.
        max_age = self.get_send_file_max_age(filename)
        return send_from_directory(
            t.cast(str, self.static_folder), filename, max_age=max_age
        )

    def open_resource(self, resource: str, mode: str = "rb") -> t.IO[t.AnyStr]:
        """Open a resource file relative to :attr:`root_path` for
        reading.

        For example, if the file ``schema.sql`` is next to the file
        ``app.py`` where the ``Flask`` app is defined, it can be opened
        with:

        .. code-block:: python

            with app.open_resource("schema.sql") as f:
                conn.executescript(f.read())

        :param resource: Path to the resource relative to
            :attr:`root_path`.
        :param mode: Open the file in this mode. Only reading is
            supported, valid values are "r" (or "rt") and "rb".

        Note this is a duplicate of the same method in the Flask
        class.

        """
        if mode not in {"r", "rt", "rb"}:
            raise ValueError("Resources can only be opened for reading.")

        return open(os.path.join(self.root_path, resource), mode)


Filepath: githubCode\src\flask\cli.py:

from __future__ import annotations

import ast
import collections.abc as cabc
import importlib.metadata
import inspect
import os
import platform
import re
import sys
import traceback
import typing as t
from functools import update_wrapper
from operator import itemgetter
from types import ModuleType

import click
from click.core import ParameterSource
from werkzeug import run_simple
from werkzeug.serving import is_running_from_reloader
from werkzeug.utils import import_string

from .globals import current_app
from .helpers import get_debug_flag
from .helpers import get_load_dotenv

if t.TYPE_CHECKING:
    import ssl

    from _typeshed.wsgi import StartResponse
    from _typeshed.wsgi import WSGIApplication
    from _typeshed.wsgi import WSGIEnvironment

    from .app import Flask


class NoAppException(click.UsageError):
    """Raised if an application cannot be found or loaded."""


def find_best_app(module: ModuleType) -> Flask:
    """Given a module instance this tries to find the best possible
    application in the module or raises an exception.
    """
    from . import Flask

    # Search for the most common names first.
    for attr_name in ("app", "application"):
        app = getattr(module, attr_name, None)

        if isinstance(app, Flask):
            return app

    # Otherwise find the only object that is a Flask instance.
    matches = [v for v in module.__dict__.values() if isinstance(v, Flask)]

    if len(matches) == 1:
        return matches[0]
    elif len(matches) > 1:
        raise NoAppException(
            "Detected multiple Flask applications in module"
            f" '{module.__name__}'. Use '{module.__name__}:name'"
            " to specify the correct one."
        )

    # Search for app factory functions.
    for attr_name in ("create_app", "make_app"):
        app_factory = getattr(module, attr_name, None)

        if inspect.isfunction(app_factory):
            try:
                app = app_factory()

                if isinstance(app, Flask):
                    return app
            except TypeError as e:
                if not _called_with_wrong_args(app_factory):
                    raise

                raise NoAppException(
                    f"Detected factory '{attr_name}' in module '{module.__name__}',"
                    " but could not call it without arguments. Use"
                    f" '{module.__name__}:{attr_name}(args)'"
                    " to specify arguments."
                ) from e

    raise NoAppException(
        "Failed to find Flask application or factory in module"
        f" '{module.__name__}'. Use '{module.__name__}:name'"
        " to specify one."
    )


def _called_with_wrong_args(f: t.Callable[..., Flask]) -> bool:
    """Check whether calling a function raised a ``TypeError`` because
    the call failed or because something in the factory raised the
    error.

    :param f: The function that was called.
    :return: ``True`` if the call failed.
    """
    tb = sys.exc_info()[2]

    try:
        while tb is not None:
            if tb.tb_frame.f_code is f.__code__:
                # In the function, it was called successfully.
                return False

            tb = tb.tb_next

        # Didn't reach the function.
        return True
    finally:
        # Delete tb to break a circular reference.
        # https://docs.python.org/2/library/sys.html#sys.exc_info
        del tb


def find_app_by_string(module: ModuleType, app_name: str) -> Flask:
    """Check if the given string is a variable name or a function. Call
    a function to get the app instance, or return the variable directly.
    """
    from . import Flask

    # Parse app_name as a single expression to determine if it's a valid
    # attribute name or function call.
    try:
        expr = ast.parse(app_name.strip(), mode="eval").body
    except SyntaxError:
        raise NoAppException(
            f"Failed to parse {app_name!r} as an attribute name or function call."
        ) from None

    if isinstance(expr, ast.Name):
        name = expr.id
        args = []
        kwargs = {}
    elif isinstance(expr, ast.Call):
        # Ensure the function name is an attribute name only.
        if not isinstance(expr.func, ast.Name):
            raise NoAppException(
                f"Function reference must be a simple name: {app_name!r}."
            )

        name = expr.func.id

        # Parse the positional and keyword arguments as literals.
        try:
            args = [ast.literal_eval(arg) for arg in expr.args]
            kwargs = {
                kw.arg: ast.literal_eval(kw.value)
                for kw in expr.keywords
                if kw.arg is not None
            }
        except ValueError:
            # literal_eval gives cryptic error messages, show a generic
            # message with the full expression instead.
            raise NoAppException(
                f"Failed to parse arguments as literal values: {app_name!r}."
            ) from None
    else:
        raise NoAppException(
            f"Failed to parse {app_name!r} as an attribute name or function call."
        )

    try:
        attr = getattr(module, name)
    except AttributeError as e:
        raise NoAppException(
            f"Failed to find attribute {name!r} in {module.__name__!r}."
        ) from e

    # If the attribute is a function, call it with any args and kwargs
    # to get the real application.
    if inspect.isfunction(attr):
        try:
            app = attr(*args, **kwargs)
        except TypeError as e:
            if not _called_with_wrong_args(attr):
                raise

            raise NoAppException(
                f"The factory {app_name!r} in module"
                f" {module.__name__!r} could not be called with the"
                " specified arguments."
            ) from e
    else:
        app = attr

    if isinstance(app, Flask):
        return app

    raise NoAppException(
        "A valid Flask application was not obtained from"
        f" '{module.__name__}:{app_name}'."
    )


def prepare_import(path: str) -> str:
    """Given a filename this will try to calculate the python path, add it
    to the search path and return the actual module name that is expected.
    """
    path = os.path.realpath(path)

    fname, ext = os.path.splitext(path)
    if ext == ".py":
        path = fname

    if os.path.basename(path) == "__init__":
        path = os.path.dirname(path)

    module_name = []

    # move up until outside package structure (no __init__.py)
    while True:
        path, name = os.path.split(path)
        module_name.append(name)

        if not os.path.exists(os.path.join(path, "__init__.py")):
            break

    if sys.path[0] != path:
        sys.path.insert(0, path)

    return ".".join(module_name[::-1])


@t.overload
def locate_app(
    module_name: str, app_name: str | None, raise_if_not_found: t.Literal[True] = True
) -> Flask:
    ...


@t.overload
def locate_app(
    module_name: str, app_name: str | None, raise_if_not_found: t.Literal[False] = ...
) -> Flask | None:
    ...


def locate_app(
    module_name: str, app_name: str | None, raise_if_not_found: bool = True
) -> Flask | None:
    try:
        __import__(module_name)
    except ImportError:
        # Reraise the ImportError if it occurred within the imported module.
        # Determine this by checking whether the trace has a depth > 1.
        if sys.exc_info()[2].tb_next:  # type: ignore[union-attr]
            raise NoAppException(
                f"While importing {module_name!r}, an ImportError was"
                f" raised:\n\n{traceback.format_exc()}"
            ) from None
        elif raise_if_not_found:
            raise NoAppException(f"Could not import {module_name!r}.") from None
        else:
            return None

    module = sys.modules[module_name]

    if app_name is None:
        return find_best_app(module)
    else:
        return find_app_by_string(module, app_name)


def get_version(ctx: click.Context, param: click.Parameter, value: t.Any) -> None:
    if not value or ctx.resilient_parsing:
        return

    flask_version = importlib.metadata.version("flask")
    werkzeug_version = importlib.metadata.version("werkzeug")

    click.echo(
        f"Python {platform.python_version()}\n"
        f"Flask {flask_version}\n"
        f"Werkzeug {werkzeug_version}",
        color=ctx.color,
    )
    ctx.exit()


version_option = click.Option(
    ["--version"],
    help="Show the Flask version.",
    expose_value=False,
    callback=get_version,
    is_flag=True,
    is_eager=True,
)


class ScriptInfo:
    """Helper object to deal with Flask applications.  This is usually not
    necessary to interface with as it's used internally in the dispatching
    to click.  In future versions of Flask this object will most likely play
    a bigger role.  Typically it's created automatically by the
    :class:`FlaskGroup` but you can also manually create it and pass it
    onwards as click object.
    """

    def __init__(
        self,
        app_import_path: str | None = None,
        create_app: t.Callable[..., Flask] | None = None,
        set_debug_flag: bool = True,
    ) -> None:
        #: Optionally the import path for the Flask application.
        self.app_import_path = app_import_path
        #: Optionally a function that is passed the script info to create
        #: the instance of the application.
        self.create_app = create_app
        #: A dictionary with arbitrary data that can be associated with
        #: this script info.
        self.data: dict[t.Any, t.Any] = {}
        self.set_debug_flag = set_debug_flag
        self._loaded_app: Flask | None = None

    def load_app(self) -> Flask:
        """Loads the Flask app (if not yet loaded) and returns it.  Calling
        this multiple times will just result in the already loaded app to
        be returned.
        """
        if self._loaded_app is not None:
            return self._loaded_app

        if self.create_app is not None:
            app: Flask | None = self.create_app()
        else:
            if self.app_import_path:
                path, name = (
                    re.split(r":(?![\\/])", self.app_import_path, maxsplit=1) + [None]
                )[:2]
                import_name = prepare_import(path)
                app = locate_app(import_name, name)
            else:
                for path in ("wsgi.py", "app.py"):
                    import_name = prepare_import(path)
                    app = locate_app(import_name, None, raise_if_not_found=False)

                    if app is not None:
                        break

        if app is None:
            raise NoAppException(
                "Could not locate a Flask application. Use the"
                " 'flask --app' option, 'FLASK_APP' environment"
                " variable, or a 'wsgi.py' or 'app.py' file in the"
                " current directory."
            )

        if self.set_debug_flag:
            # Update the app's debug flag through the descriptor so that
            # other values repopulate as well.
            app.debug = get_debug_flag()

        self._loaded_app = app
        return app


pass_script_info = click.make_pass_decorator(ScriptInfo, ensure=True)

F = t.TypeVar("F", bound=t.Callable[..., t.Any])


def with_appcontext(f: F) -> F:
    """Wraps a callback so that it's guaranteed to be executed with the
    script's application context.

    Custom commands (and their options) registered under ``app.cli`` or
    ``blueprint.cli`` will always have an app context available, this
    decorator is not required in that case.

    .. versionchanged:: 2.2
        The app context is active for subcommands as well as the
        decorated callback. The app context is always available to
        ``app.cli`` command and parameter callbacks.
    """

    @click.pass_context
    def decorator(ctx: click.Context, /, *args: t.Any, **kwargs: t.Any) -> t.Any:
        if not current_app:
            app = ctx.ensure_object(ScriptInfo).load_app()
            ctx.with_resource(app.app_context())

        return ctx.invoke(f, *args, **kwargs)

    return update_wrapper(decorator, f)  # type: ignore[return-value]


class AppGroup(click.Group):
    """This works similar to a regular click :class:`~click.Group` but it
    changes the behavior of the :meth:`command` decorator so that it
    automatically wraps the functions in :func:`with_appcontext`.

    Not to be confused with :class:`FlaskGroup`.
    """

    def command(  # type: ignore[override]
        self, *args: t.Any, **kwargs: t.Any
    ) -> t.Callable[[t.Callable[..., t.Any]], click.Command]:
        """This works exactly like the method of the same name on a regular
        :class:`click.Group` but it wraps callbacks in :func:`with_appcontext`
        unless it's disabled by passing ``with_appcontext=False``.
        """
        wrap_for_ctx = kwargs.pop("with_appcontext", True)

        def decorator(f: t.Callable[..., t.Any]) -> click.Command:
            if wrap_for_ctx:
                f = with_appcontext(f)
            return super(AppGroup, self).command(*args, **kwargs)(f)  # type: ignore[no-any-return]

        return decorator

    def group(  # type: ignore[override]
        self, *args: t.Any, **kwargs: t.Any
    ) -> t.Callable[[t.Callable[..., t.Any]], click.Group]:
        """This works exactly like the method of the same name on a regular
        :class:`click.Group` but it defaults the group class to
        :class:`AppGroup`.
        """
        kwargs.setdefault("cls", AppGroup)
        return super().group(*args, **kwargs)  # type: ignore[no-any-return]


def _set_app(ctx: click.Context, param: click.Option, value: str | None) -> str | None:
    if value is None:
        return None

    info = ctx.ensure_object(ScriptInfo)
    info.app_import_path = value
    return value


# This option is eager so the app will be available if --help is given.
# --help is also eager, so --app must be before it in the param list.
# no_args_is_help bypasses eager processing, so this option must be
# processed manually in that case to ensure FLASK_APP gets picked up.
_app_option = click.Option(
    ["-A", "--app"],
    metavar="IMPORT",
    help=(
        "The Flask application or factory function to load, in the form 'module:name'."
        " Module can be a dotted import or file path. Name is not required if it is"
        " 'app', 'application', 'create_app', or 'make_app', and can be 'name(args)' to"
        " pass arguments."
    ),
    is_eager=True,
    expose_value=False,
    callback=_set_app,
)


def _set_debug(ctx: click.Context, param: click.Option, value: bool) -> bool | None:
    # If the flag isn't provided, it will default to False. Don't use
    # that, let debug be set by env in that case.
    source = ctx.get_parameter_source(param.name)  # type: ignore[arg-type]

    if source is not None and source in (
        ParameterSource.DEFAULT,
        ParameterSource.DEFAULT_MAP,
    ):
        return None

    # Set with env var instead of ScriptInfo.load so that it can be
    # accessed early during a factory function.
    os.environ["FLASK_DEBUG"] = "1" if value else "0"
    return value


_debug_option = click.Option(
    ["--debug/--no-debug"],
    help="Set debug mode.",
    expose_value=False,
    callback=_set_debug,
)


def _env_file_callback(
    ctx: click.Context, param: click.Option, value: str | None
) -> str | None:
    if value is None:
        return None

    import importlib

    try:
        importlib.import_module("dotenv")
    except ImportError:
        raise click.BadParameter(
            "python-dotenv must be installed to load an env file.",
            ctx=ctx,
            param=param,
        ) from None

    # Don't check FLASK_SKIP_DOTENV, that only disables automatically
    # loading .env and .flaskenv files.
    load_dotenv(value)
    return value


# This option is eager so env vars are loaded as early as possible to be
# used by other options.
_env_file_option = click.Option(
    ["-e", "--env-file"],
    type=click.Path(exists=True, dir_okay=False),
    help="Load environment variables from this file. python-dotenv must be installed.",
    is_eager=True,
    expose_value=False,
    callback=_env_file_callback,
)


class FlaskGroup(AppGroup):
    """Special subclass of the :class:`AppGroup` group that supports
    loading more commands from the configured Flask app.  Normally a
    developer does not have to interface with this class but there are
    some very advanced use cases for which it makes sense to create an
    instance of this. see :ref:`custom-scripts`.

    :param add_default_commands: if this is True then the default run and
        shell commands will be added.
    :param add_version_option: adds the ``--version`` option.
    :param create_app: an optional callback that is passed the script info and
        returns the loaded app.
    :param load_dotenv: Load the nearest :file:`.env` and :file:`.flaskenv`
        files to set environment variables. Will also change the working
        directory to the directory containing the first file found.
    :param set_debug_flag: Set the app's debug flag.

    .. versionchanged:: 2.2
        Added the ``-A/--app``, ``--debug/--no-debug``, ``-e/--env-file`` options.

    .. versionchanged:: 2.2
        An app context is pushed when running ``app.cli`` commands, so
        ``@with_appcontext`` is no longer required for those commands.

    .. versionchanged:: 1.0
        If installed, python-dotenv will be used to load environment variables
        from :file:`.env` and :file:`.flaskenv` files.
    """

    def __init__(
        self,
        add_default_commands: bool = True,
        create_app: t.Callable[..., Flask] | None = None,
        add_version_option: bool = True,
        load_dotenv: bool = True,
        set_debug_flag: bool = True,
        **extra: t.Any,
    ) -> None:
        params = list(extra.pop("params", None) or ())
        # Processing is done with option callbacks instead of a group
        # callback. This allows users to make a custom group callback
        # without losing the behavior. --env-file must come first so
        # that it is eagerly evaluated before --app.
        params.extend((_env_file_option, _app_option, _debug_option))

        if add_version_option:
            params.append(version_option)

        if "context_settings" not in extra:
            extra["context_settings"] = {}

        extra["context_settings"].setdefault("auto_envvar_prefix", "FLASK")

        super().__init__(params=params, **extra)

        self.create_app = create_app
        self.load_dotenv = load_dotenv
        self.set_debug_flag = set_debug_flag

        if add_default_commands:
            self.add_command(run_command)
            self.add_command(shell_command)
            self.add_command(routes_command)

        self._loaded_plugin_commands = False

    def _load_plugin_commands(self) -> None:
        if self._loaded_plugin_commands:
            return

        if sys.version_info >= (3, 10):
            from importlib import metadata
        else:
            # Use a backport on Python < 3.10. We technically have
            # importlib.metadata on 3.8+, but the API changed in 3.10,
            # so use the backport for consistency.
            import importlib_metadata as metadata

        for ep in metadata.entry_points(group="flask.commands"):
            self.add_command(ep.load(), ep.name)

        self._loaded_plugin_commands = True

    def get_command(self, ctx: click.Context, name: str) -> click.Command | None:
        self._load_plugin_commands()
        # Look up built-in and plugin commands, which should be
        # available even if the app fails to load.
        rv = super().get_command(ctx, name)

        if rv is not None:
            return rv

        info = ctx.ensure_object(ScriptInfo)

        # Look up commands provided by the app, showing an error and
        # continuing if the app couldn't be loaded.
        try:
            app = info.load_app()
        except NoAppException as e:
            click.secho(f"Error: {e.format_message()}\n", err=True, fg="red")
            return None

        # Push an app context for the loaded app unless it is already
        # active somehow. This makes the context available to parameter
        # and command callbacks without needing @with_appcontext.
        if not current_app or current_app._get_current_object() is not app:  # type: ignore[attr-defined]
            ctx.with_resource(app.app_context())

        return app.cli.get_command(ctx, name)

    def list_commands(self, ctx: click.Context) -> list[str]:
        self._load_plugin_commands()
        # Start with the built-in and plugin commands.
        rv = set(super().list_commands(ctx))
        info = ctx.ensure_object(ScriptInfo)

        # Add commands provided by the app, showing an error and
        # continuing if the app couldn't be loaded.
        try:
            rv.update(info.load_app().cli.list_commands(ctx))
        except NoAppException as e:
            # When an app couldn't be loaded, show the error message
            # without the traceback.
            click.secho(f"Error: {e.format_message()}\n", err=True, fg="red")
        except Exception:
            # When any other errors occurred during loading, show the
            # full traceback.
            click.secho(f"{traceback.format_exc()}\n", err=True, fg="red")

        return sorted(rv)

    def make_context(
        self,
        info_name: str | None,
        args: list[str],
        parent: click.Context | None = None,
        **extra: t.Any,
    ) -> click.Context:
        # Set a flag to tell app.run to become a no-op. If app.run was
        # not in a __name__ == __main__ guard, it would start the server
        # when importing, blocking whatever command is being called.
        os.environ["FLASK_RUN_FROM_CLI"] = "true"

        # Attempt to load .env and .flask env files. The --env-file
        # option can cause another file to be loaded.
        if get_load_dotenv(self.load_dotenv):
            load_dotenv()

        if "obj" not in extra and "obj" not in self.context_settings:
            extra["obj"] = ScriptInfo(
                create_app=self.create_app, set_debug_flag=self.set_debug_flag
            )

        return super().make_context(info_name, args, parent=parent, **extra)

    def parse_args(self, ctx: click.Context, args: list[str]) -> list[str]:
        if not args and self.no_args_is_help:
            # Attempt to load --env-file and --app early in case they
            # were given as env vars. Otherwise no_args_is_help will not
            # see commands from app.cli.
            _env_file_option.handle_parse_result(ctx, {}, [])
            _app_option.handle_parse_result(ctx, {}, [])

        return super().parse_args(ctx, args)


def _path_is_ancestor(path: str, other: str) -> bool:
    """Take ``other`` and remove the length of ``path`` from it. Then join it
    to ``path``. If it is the original value, ``path`` is an ancestor of
    ``other``."""
    return os.path.join(path, other[len(path) :].lstrip(os.sep)) == other


def load_dotenv(path: str | os.PathLike[str] | None = None) -> bool:
    """Load "dotenv" files in order of precedence to set environment variables.

    If an env var is already set it is not overwritten, so earlier files in the
    list are preferred over later files.

    This is a no-op if `python-dotenv`_ is not installed.

    .. _python-dotenv: https://github.com/theskumar/python-dotenv#readme

    :param path: Load the file at this location instead of searching.
    :return: ``True`` if a file was loaded.

    .. versionchanged:: 2.0
        The current directory is not changed to the location of the
        loaded file.

    .. versionchanged:: 2.0
        When loading the env files, set the default encoding to UTF-8.

    .. versionchanged:: 1.1.0
        Returns ``False`` when python-dotenv is not installed, or when
        the given path isn't a file.

    .. versionadded:: 1.0
    """
    try:
        import dotenv
    except ImportError:
        if path or os.path.isfile(".env") or os.path.isfile(".flaskenv"):
            click.secho(
                " * Tip: There are .env or .flaskenv files present."
                ' Do "pip install python-dotenv" to use them.',
                fg="yellow",
                err=True,
            )

        return False

    # Always return after attempting to load a given path, don't load
    # the default files.
    if path is not None:
        if os.path.isfile(path):
            return dotenv.load_dotenv(path, encoding="utf-8")

        return False

    loaded = False

    for name in (".env", ".flaskenv"):
        path = dotenv.find_dotenv(name, usecwd=True)

        if not path:
            continue

        dotenv.load_dotenv(path, encoding="utf-8")
        loaded = True

    return loaded  # True if at least one file was located and loaded.


def show_server_banner(debug: bool, app_import_path: str | None) -> None:
    """Show extra startup messages the first time the server is run,
    ignoring the reloader.
    """
    if is_running_from_reloader():
        return

    if app_import_path is not None:
        click.echo(f" * Serving Flask app '{app_import_path}'")

    if debug is not None:
        click.echo(f" * Debug mode: {'on' if debug else 'off'}")


class CertParamType(click.ParamType):
    """Click option type for the ``--cert`` option. Allows either an
    existing file, the string ``'adhoc'``, or an import for a
    :class:`~ssl.SSLContext` object.
    """

    name = "path"

    def __init__(self) -> None:
        self.path_type = click.Path(exists=True, dir_okay=False, resolve_path=True)

    def convert(
        self, value: t.Any, param: click.Parameter | None, ctx: click.Context | None
    ) -> t.Any:
        try:
            import ssl
        except ImportError:
            raise click.BadParameter(
                'Using "--cert" requires Python to be compiled with SSL support.',
                ctx,
                param,
            ) from None

        try:
            return self.path_type(value, param, ctx)
        except click.BadParameter:
            value = click.STRING(value, param, ctx).lower()

            if value == "adhoc":
                try:
                    import cryptography  # noqa: F401
                except ImportError:
                    raise click.BadParameter(
                        "Using ad-hoc certificates requires the cryptography library.",
                        ctx,
                        param,
                    ) from None

                return value

            obj = import_string(value, silent=True)

            if isinstance(obj, ssl.SSLContext):
                return obj

            raise


def _validate_key(ctx: click.Context, param: click.Parameter, value: t.Any) -> t.Any:
    """The ``--key`` option must be specified when ``--cert`` is a file.
    Modifies the ``cert`` param to be a ``(cert, key)`` pair if needed.
    """
    cert = ctx.params.get("cert")
    is_adhoc = cert == "adhoc"

    try:
        import ssl
    except ImportError:
        is_context = False
    else:
        is_context = isinstance(cert, ssl.SSLContext)

    if value is not None:
        if is_adhoc:
            raise click.BadParameter(
                'When "--cert" is "adhoc", "--key" is not used.', ctx, param
            )

        if is_context:
            raise click.BadParameter(
                'When "--cert" is an SSLContext object, "--key" is not used.',
                ctx,
                param,
            )

        if not cert:
            raise click.BadParameter('"--cert" must also be specified.', ctx, param)

        ctx.params["cert"] = cert, value

    else:
        if cert and not (is_adhoc or is_context):
            raise click.BadParameter('Required when using "--cert".', ctx, param)

    return value


class SeparatedPathType(click.Path):
    """Click option type that accepts a list of values separated by the
    OS's path separator (``:``, ``;`` on Windows). Each value is
    validated as a :class:`click.Path` type.
    """

    def convert(
        self, value: t.Any, param: click.Parameter | None, ctx: click.Context | None
    ) -> t.Any:
        items = self.split_envvar_value(value)
        # can't call no-arg super() inside list comprehension until Python 3.12
        super_convert = super().convert
        return [super_convert(item, param, ctx) for item in items]


@click.command("run", short_help="Run a development server.")
@click.option("--host", "-h", default="127.0.0.1", help="The interface to bind to.")
@click.option("--port", "-p", default=5000, help="The port to bind to.")
@click.option(
    "--cert",
    type=CertParamType(),
    help="Specify a certificate file to use HTTPS.",
    is_eager=True,
)
@click.option(
    "--key",
    type=click.Path(exists=True, dir_okay=False, resolve_path=True),
    callback=_validate_key,
    expose_value=False,
    help="The key file to use when specifying a certificate.",
)
@click.option(
    "--reload/--no-reload",
    default=None,
    help="Enable or disable the reloader. By default the reloader "
    "is active if debug is enabled.",
)
@click.option(
    "--debugger/--no-debugger",
    default=None,
    help="Enable or disable the debugger. By default the debugger "
    "is active if debug is enabled.",
)
@click.option(
    "--with-threads/--without-threads",
    default=True,
    help="Enable or disable multithreading.",
)
@click.option(
    "--extra-files",
    default=None,
    type=SeparatedPathType(),
    help=(
        "Extra files that trigger a reload on change. Multiple paths"
        f" are separated by {os.path.pathsep!r}."
    ),
)
@click.option(
    "--exclude-patterns",
    default=None,
    type=SeparatedPathType(),
    help=(
        "Files matching these fnmatch patterns will not trigger a reload"
        " on change. Multiple patterns are separated by"
        f" {os.path.pathsep!r}."
    ),
)
@pass_script_info
def run_command(
    info: ScriptInfo,
    host: str,
    port: int,
    reload: bool,
    debugger: bool,
    with_threads: bool,
    cert: ssl.SSLContext | tuple[str, str | None] | t.Literal["adhoc"] | None,
    extra_files: list[str] | None,
    exclude_patterns: list[str] | None,
) -> None:
    """Run a local development server.

    This server is for development purposes only. It does not provide
    the stability, security, or performance of production WSGI servers.

    The reloader and debugger are enabled by default with the '--debug'
    option.
    """
    try:
        app: WSGIApplication = info.load_app()
    except Exception as e:
        if is_running_from_reloader():
            # When reloading, print out the error immediately, but raise
            # it later so the debugger or server can handle it.
            traceback.print_exc()
            err = e

            def app(
                environ: WSGIEnvironment, start_response: StartResponse
            ) -> cabc.Iterable[bytes]:
                raise err from None

        else:
            # When not reloading, raise the error immediately so the
            # command fails.
            raise e from None

    debug = get_debug_flag()

    if reload is None:
        reload = debug

    if debugger is None:
        debugger = debug

    show_server_banner(debug, info.app_import_path)

    run_simple(
        host,
        port,
        app,
        use_reloader=reload,
        use_debugger=debugger,
        threaded=with_threads,
        ssl_context=cert,
        extra_files=extra_files,
        exclude_patterns=exclude_patterns,
    )


run_command.params.insert(0, _debug_option)


@click.command("shell", short_help="Run a shell in the app context.")
@with_appcontext
def shell_command() -> None:
    """Run an interactive Python shell in the context of a given
    Flask application.  The application will populate the default
    namespace of this shell according to its configuration.

    This is useful for executing small snippets of management code
    without having to manually configure the application.
    """
    import code

    banner = (
        f"Python {sys.version} on {sys.platform}\n"
        f"App: {current_app.import_name}\n"
        f"Instance: {current_app.instance_path}"
    )
    ctx: dict[str, t.Any] = {}

    # Support the regular Python interpreter startup script if someone
    # is using it.
    startup = os.environ.get("PYTHONSTARTUP")
    if startup and os.path.isfile(startup):
        with open(startup) as f:
            eval(compile(f.read(), startup, "exec"), ctx)

    ctx.update(current_app.make_shell_context())

    # Site, customize, or startup script can set a hook to call when
    # entering interactive mode. The default one sets up readline with
    # tab and history completion.
    interactive_hook = getattr(sys, "__interactivehook__", None)

    if interactive_hook is not None:
        try:
            import readline
            from rlcompleter import Completer
        except ImportError:
            pass
        else:
            # rlcompleter uses __main__.__dict__ by default, which is
            # flask.__main__. Use the shell context instead.
            readline.set_completer(Completer(ctx).complete)

        interactive_hook()

    code.interact(banner=banner, local=ctx)


@click.command("routes", short_help="Show the routes for the app.")
@click.option(
    "--sort",
    "-s",
    type=click.Choice(("endpoint", "methods", "domain", "rule", "match")),
    default="endpoint",
    help=(
        "Method to sort routes by. 'match' is the order that Flask will match routes"
        " when dispatching a request."
    ),
)
@click.option("--all-methods", is_flag=True, help="Show HEAD and OPTIONS methods.")
@with_appcontext
def routes_command(sort: str, all_methods: bool) -> None:
    """Show all registered routes with endpoints and methods."""
    rules = list(current_app.url_map.iter_rules())

    if not rules:
        click.echo("No routes were registered.")
        return

    ignored_methods = set() if all_methods else {"HEAD", "OPTIONS"}
    host_matching = current_app.url_map.host_matching
    has_domain = any(rule.host if host_matching else rule.subdomain for rule in rules)
    rows = []

    for rule in rules:
        row = [
            rule.endpoint,
            ", ".join(sorted((rule.methods or set()) - ignored_methods)),
        ]

        if has_domain:
            row.append((rule.host if host_matching else rule.subdomain) or "")

        row.append(rule.rule)
        rows.append(row)

    headers = ["Endpoint", "Methods"]
    sorts = ["endpoint", "methods"]

    if has_domain:
        headers.append("Host" if host_matching else "Subdomain")
        sorts.append("domain")

    headers.append("Rule")
    sorts.append("rule")

    try:
        rows.sort(key=itemgetter(sorts.index(sort)))
    except ValueError:
        pass

    rows.insert(0, headers)
    widths = [max(len(row[i]) for row in rows) for i in range(len(headers))]
    rows.insert(1, ["-" * w for w in widths])
    template = "  ".join(f"{{{i}:<{w}}}" for i, w in enumerate(widths))

    for row in rows:
        click.echo(template.format(*row))


cli = FlaskGroup(
    name="flask",
    help="""\
A general utility script for Flask applications.

An application to load must be given with the '--app' option,
'FLASK_APP' environment variable, or with a 'wsgi.py' or 'app.py' file
in the current directory.
""",
)


def main() -> None:
    cli.main()


if __name__ == "__main__":
    main()


Filepath: githubCode\src\flask\config.py:

from __future__ import annotations

import errno
import json
import os
import types
import typing as t

from werkzeug.utils import import_string

if t.TYPE_CHECKING:
    import typing_extensions as te

    from .sansio.app import App


T = t.TypeVar("T")


class ConfigAttribute(t.Generic[T]):
    """Makes an attribute forward to the config"""

    def __init__(
        self, name: str, get_converter: t.Callable[[t.Any], T] | None = None
    ) -> None:
        self.__name__ = name
        self.get_converter = get_converter

    @t.overload
    def __get__(self, obj: None, owner: None) -> te.Self:
        ...

    @t.overload
    def __get__(self, obj: App, owner: type[App]) -> T:
        ...

    def __get__(self, obj: App | None, owner: type[App] | None = None) -> T | te.Self:
        if obj is None:
            return self

        rv = obj.config[self.__name__]

        if self.get_converter is not None:
            rv = self.get_converter(rv)

        return rv  # type: ignore[no-any-return]

    def __set__(self, obj: App, value: t.Any) -> None:
        obj.config[self.__name__] = value


class Config(dict):  # type: ignore[type-arg]
    """Works exactly like a dict but provides ways to fill it from files
    or special dictionaries.  There are two common patterns to populate the
    config.

    Either you can fill the config from a config file::

        app.config.from_pyfile('yourconfig.cfg')

    Or alternatively you can define the configuration options in the
    module that calls :meth:`from_object` or provide an import path to
    a module that should be loaded.  It is also possible to tell it to
    use the same module and with that provide the configuration values
    just before the call::

        DEBUG = True
        SECRET_KEY = 'development key'
        app.config.from_object(__name__)

    In both cases (loading from any Python file or loading from modules),
    only uppercase keys are added to the config.  This makes it possible to use
    lowercase values in the config file for temporary values that are not added
    to the config or to define the config keys in the same file that implements
    the application.

    Probably the most interesting way to load configurations is from an
    environment variable pointing to a file::

        app.config.from_envvar('YOURAPPLICATION_SETTINGS')

    In this case before launching the application you have to set this
    environment variable to the file you want to use.  On Linux and OS X
    use the export statement::

        export YOURAPPLICATION_SETTINGS='/path/to/config/file'

    On windows use `set` instead.

    :param root_path: path to which files are read relative from.  When the
                      config object is created by the application, this is
                      the application's :attr:`~flask.Flask.root_path`.
    :param defaults: an optional dictionary of default values
    """

    def __init__(
        self,
        root_path: str | os.PathLike[str],
        defaults: dict[str, t.Any] | None = None,
    ) -> None:
        super().__init__(defaults or {})
        self.root_path = root_path

    def from_envvar(self, variable_name: str, silent: bool = False) -> bool:
        """Loads a configuration from an environment variable pointing to
        a configuration file.  This is basically just a shortcut with nicer
        error messages for this line of code::

            app.config.from_pyfile(os.environ['YOURAPPLICATION_SETTINGS'])

        :param variable_name: name of the environment variable
        :param silent: set to ``True`` if you want silent failure for missing
                       files.
        :return: ``True`` if the file was loaded successfully.
        """
        rv = os.environ.get(variable_name)
        if not rv:
            if silent:
                return False
            raise RuntimeError(
                f"The environment variable {variable_name!r} is not set"
                " and as such configuration could not be loaded. Set"
                " this variable and make it point to a configuration"
                " file"
            )
        return self.from_pyfile(rv, silent=silent)

    def from_prefixed_env(
        self, prefix: str = "FLASK", *, loads: t.Callable[[str], t.Any] = json.loads
    ) -> bool:
        """Load any environment variables that start with ``FLASK_``,
        dropping the prefix from the env key for the config key. Values
        are passed through a loading function to attempt to convert them
        to more specific types than strings.

        Keys are loaded in :func:`sorted` order.

        The default loading function attempts to parse values as any
        valid JSON type, including dicts and lists.

        Specific items in nested dicts can be set by separating the
        keys with double underscores (``__``). If an intermediate key
        doesn't exist, it will be initialized to an empty dict.

        :param prefix: Load env vars that start with this prefix,
            separated with an underscore (``_``).
        :param loads: Pass each string value to this function and use
            the returned value as the config value. If any error is
            raised it is ignored and the value remains a string. The
            default is :func:`json.loads`.

        .. versionadded:: 2.1
        """
        prefix = f"{prefix}_"
        len_prefix = len(prefix)

        for key in sorted(os.environ):
            if not key.startswith(prefix):
                continue

            value = os.environ[key]

            try:
                value = loads(value)
            except Exception:
                # Keep the value as a string if loading failed.
                pass

            # Change to key.removeprefix(prefix) on Python >= 3.9.
            key = key[len_prefix:]

            if "__" not in key:
                # A non-nested key, set directly.
                self[key] = value
                continue

            # Traverse nested dictionaries with keys separated by "__".
            current = self
            *parts, tail = key.split("__")

            for part in parts:
                # If an intermediate dict does not exist, create it.
                if part not in current:
                    current[part] = {}

                current = current[part]

            current[tail] = value

        return True

    def from_pyfile(
        self, filename: str | os.PathLike[str], silent: bool = False
    ) -> bool:
        """Updates the values in the config from a Python file.  This function
        behaves as if the file was imported as module with the
        :meth:`from_object` function.

        :param filename: the filename of the config.  This can either be an
                         absolute filename or a filename relative to the
                         root path.
        :param silent: set to ``True`` if you want silent failure for missing
                       files.
        :return: ``True`` if the file was loaded successfully.

        .. versionadded:: 0.7
           `silent` parameter.
        """
        filename = os.path.join(self.root_path, filename)
        d = types.ModuleType("config")
        d.__file__ = filename
        try:
            with open(filename, mode="rb") as config_file:
                exec(compile(config_file.read(), filename, "exec"), d.__dict__)
        except OSError as e:
            if silent and e.errno in (errno.ENOENT, errno.EISDIR, errno.ENOTDIR):
                return False
            e.strerror = f"Unable to load configuration file ({e.strerror})"
            raise
        self.from_object(d)
        return True

    def from_object(self, obj: object | str) -> None:
        """Updates the values from the given object.  An object can be of one
        of the following two types:

        -   a string: in this case the object with that name will be imported
        -   an actual object reference: that object is used directly

        Objects are usually either modules or classes. :meth:`from_object`
        loads only the uppercase attributes of the module/class. A ``dict``
        object will not work with :meth:`from_object` because the keys of a
        ``dict`` are not attributes of the ``dict`` class.

        Example of module-based configuration::

            app.config.from_object('yourapplication.default_config')
            from yourapplication import default_config
            app.config.from_object(default_config)

        Nothing is done to the object before loading. If the object is a
        class and has ``@property`` attributes, it needs to be
        instantiated before being passed to this method.

        You should not use this function to load the actual configuration but
        rather configuration defaults.  The actual config should be loaded
        with :meth:`from_pyfile` and ideally from a location not within the
        package because the package might be installed system wide.

        See :ref:`config-dev-prod` for an example of class-based configuration
        using :meth:`from_object`.

        :param obj: an import name or object
        """
        if isinstance(obj, str):
            obj = import_string(obj)
        for key in dir(obj):
            if key.isupper():
                self[key] = getattr(obj, key)

    def from_file(
        self,
        filename: str | os.PathLike[str],
        load: t.Callable[[t.IO[t.Any]], t.Mapping[str, t.Any]],
        silent: bool = False,
        text: bool = True,
    ) -> bool:
        """Update the values in the config from a file that is loaded
        using the ``load`` parameter. The loaded data is passed to the
        :meth:`from_mapping` method.

        .. code-block:: python

            import json
            app.config.from_file("config.json", load=json.load)

            import tomllib
            app.config.from_file("config.toml", load=tomllib.load, text=False)

        :param filename: The path to the data file. This can be an
            absolute path or relative to the config root path.
        :param load: A callable that takes a file handle and returns a
            mapping of loaded data from the file.
        :type load: ``Callable[[Reader], Mapping]`` where ``Reader``
            implements a ``read`` method.
        :param silent: Ignore the file if it doesn't exist.
        :param text: Open the file in text or binary mode.
        :return: ``True`` if the file was loaded successfully.

        .. versionchanged:: 2.3
            The ``text`` parameter was added.

        .. versionadded:: 2.0
        """
        filename = os.path.join(self.root_path, filename)

        try:
            with open(filename, "r" if text else "rb") as f:
                obj = load(f)
        except OSError as e:
            if silent and e.errno in (errno.ENOENT, errno.EISDIR):
                return False

            e.strerror = f"Unable to load configuration file ({e.strerror})"
            raise

        return self.from_mapping(obj)

    def from_mapping(
        self, mapping: t.Mapping[str, t.Any] | None = None, **kwargs: t.Any
    ) -> bool:
        """Updates the config like :meth:`update` ignoring items with
        non-upper keys.

        :return: Always returns ``True``.

        .. versionadded:: 0.11
        """
        mappings: dict[str, t.Any] = {}
        if mapping is not None:
            mappings.update(mapping)
        mappings.update(kwargs)
        for key, value in mappings.items():
            if key.isupper():
                self[key] = value
        return True

    def get_namespace(
        self, namespace: str, lowercase: bool = True, trim_namespace: bool = True
    ) -> dict[str, t.Any]:
        """Returns a dictionary containing a subset of configuration options
        that match the specified namespace/prefix. Example usage::

            app.config['IMAGE_STORE_TYPE'] = 'fs'
            app.config['IMAGE_STORE_PATH'] = '/var/app/images'
            app.config['IMAGE_STORE_BASE_URL'] = 'http://img.website.com'
            image_store_config = app.config.get_namespace('IMAGE_STORE_')

        The resulting dictionary `image_store_config` would look like::

            {
                'type': 'fs',
                'path': '/var/app/images',
                'base_url': 'http://img.website.com'
            }

        This is often useful when configuration options map directly to
        keyword arguments in functions or class constructors.

        :param namespace: a configuration namespace
        :param lowercase: a flag indicating if the keys of the resulting
                          dictionary should be lowercase
        :param trim_namespace: a flag indicating if the keys of the resulting
                          dictionary should not include the namespace

        .. versionadded:: 0.11
        """
        rv = {}
        for k, v in self.items():
            if not k.startswith(namespace):
                continue
            if trim_namespace:
                key = k[len(namespace) :]
            else:
                key = k
            if lowercase:
                key = key.lower()
            rv[key] = v
        return rv

    def __repr__(self) -> str:
        return f"<{type(self).__name__} {dict.__repr__(self)}>"


Filepath: githubCode\src\flask\ctx.py:

from __future__ import annotations

import contextvars
import sys
import typing as t
from functools import update_wrapper
from types import TracebackType

from werkzeug.exceptions import HTTPException

from . import typing as ft
from .globals import _cv_app
from .globals import _cv_request
from .signals import appcontext_popped
from .signals import appcontext_pushed

if t.TYPE_CHECKING:  # pragma: no cover
    from _typeshed.wsgi import WSGIEnvironment

    from .app import Flask
    from .sessions import SessionMixin
    from .wrappers import Request


# a singleton sentinel value for parameter defaults
_sentinel = object()


class _AppCtxGlobals:
    """A plain object. Used as a namespace for storing data during an
    application context.

    Creating an app context automatically creates this object, which is
    made available as the :data:`g` proxy.

    .. describe:: 'key' in g

        Check whether an attribute is present.

        .. versionadded:: 0.10

    .. describe:: iter(g)

        Return an iterator over the attribute names.

        .. versionadded:: 0.10
    """

    # Define attr methods to let mypy know this is a namespace object
    # that has arbitrary attributes.

    def __getattr__(self, name: str) -> t.Any:
        try:
            return self.__dict__[name]
        except KeyError:
            raise AttributeError(name) from None

    def __setattr__(self, name: str, value: t.Any) -> None:
        self.__dict__[name] = value

    def __delattr__(self, name: str) -> None:
        try:
            del self.__dict__[name]
        except KeyError:
            raise AttributeError(name) from None

    def get(self, name: str, default: t.Any | None = None) -> t.Any:
        """Get an attribute by name, or a default value. Like
        :meth:`dict.get`.

        :param name: Name of attribute to get.
        :param default: Value to return if the attribute is not present.

        .. versionadded:: 0.10
        """
        return self.__dict__.get(name, default)

    def pop(self, name: str, default: t.Any = _sentinel) -> t.Any:
        """Get and remove an attribute by name. Like :meth:`dict.pop`.

        :param name: Name of attribute to pop.
        :param default: Value to return if the attribute is not present,
            instead of raising a ``KeyError``.

        .. versionadded:: 0.11
        """
        if default is _sentinel:
            return self.__dict__.pop(name)
        else:
            return self.__dict__.pop(name, default)

    def setdefault(self, name: str, default: t.Any = None) -> t.Any:
        """Get the value of an attribute if it is present, otherwise
        set and return a default value. Like :meth:`dict.setdefault`.

        :param name: Name of attribute to get.
        :param default: Value to set and return if the attribute is not
            present.

        .. versionadded:: 0.11
        """
        return self.__dict__.setdefault(name, default)

    def __contains__(self, item: str) -> bool:
        return item in self.__dict__

    def __iter__(self) -> t.Iterator[str]:
        return iter(self.__dict__)

    def __repr__(self) -> str:
        ctx = _cv_app.get(None)
        if ctx is not None:
            return f"<flask.g of '{ctx.app.name}'>"
        return object.__repr__(self)


def after_this_request(
    f: ft.AfterRequestCallable[t.Any],
) -> ft.AfterRequestCallable[t.Any]:
    """Executes a function after this request.  This is useful to modify
    response objects.  The function is passed the response object and has
    to return the same or a new one.

    Example::

        @app.route('/')
        def index():
            @after_this_request
            def add_header(response):
                response.headers['X-Foo'] = 'Parachute'
                return response
            return 'Hello World!'

    This is more useful if a function other than the view function wants to
    modify a response.  For instance think of a decorator that wants to add
    some headers without converting the return value into a response object.

    .. versionadded:: 0.9
    """
    ctx = _cv_request.get(None)

    if ctx is None:
        raise RuntimeError(
            "'after_this_request' can only be used when a request"
            " context is active, such as in a view function."
        )

    ctx._after_request_functions.append(f)
    return f


F = t.TypeVar("F", bound=t.Callable[..., t.Any])


def copy_current_request_context(f: F) -> F:
    """A helper function that decorates a function to retain the current
    request context.  This is useful when working with greenlets.  The moment
    the function is decorated a copy of the request context is created and
    then pushed when the function is called.  The current session is also
    included in the copied request context.

    Example::

        import gevent
        from flask import copy_current_request_context

        @app.route('/')
        def index():
            @copy_current_request_context
            def do_some_work():
                # do some work here, it can access flask.request or
                # flask.session like you would otherwise in the view function.
                ...
            gevent.spawn(do_some_work)
            return 'Regular response'

    .. versionadded:: 0.10
    """
    ctx = _cv_request.get(None)

    if ctx is None:
        raise RuntimeError(
            "'copy_current_request_context' can only be used when a"
            " request context is active, such as in a view function."
        )

    ctx = ctx.copy()

    def wrapper(*args: t.Any, **kwargs: t.Any) -> t.Any:
        with ctx:  # type: ignore[union-attr]
            return ctx.app.ensure_sync(f)(*args, **kwargs)  # type: ignore[union-attr]

    return update_wrapper(wrapper, f)  # type: ignore[return-value]


def has_request_context() -> bool:
    """If you have code that wants to test if a request context is there or
    not this function can be used.  For instance, you may want to take advantage
    of request information if the request object is available, but fail
    silently if it is unavailable.

    ::

        class User(db.Model):

            def __init__(self, username, remote_addr=None):
                self.username = username
                if remote_addr is None and has_request_context():
                    remote_addr = request.remote_addr
                self.remote_addr = remote_addr

    Alternatively you can also just test any of the context bound objects
    (such as :class:`request` or :class:`g`) for truthness::

        class User(db.Model):

            def __init__(self, username, remote_addr=None):
                self.username = username
                if remote_addr is None and request:
                    remote_addr = request.remote_addr
                self.remote_addr = remote_addr

    .. versionadded:: 0.7
    """
    return _cv_request.get(None) is not None


def has_app_context() -> bool:
    """Works like :func:`has_request_context` but for the application
    context.  You can also just do a boolean check on the
    :data:`current_app` object instead.

    .. versionadded:: 0.9
    """
    return _cv_app.get(None) is not None


class AppContext:
    """The app context contains application-specific information. An app
    context is created and pushed at the beginning of each request if
    one is not already active. An app context is also pushed when
    running CLI commands.
    """

    def __init__(self, app: Flask) -> None:
        self.app = app
        self.url_adapter = app.create_url_adapter(None)
        self.g: _AppCtxGlobals = app.app_ctx_globals_class()
        self._cv_tokens: list[contextvars.Token[AppContext]] = []

    def push(self) -> None:
        """Binds the app context to the current context."""
        self._cv_tokens.append(_cv_app.set(self))
        appcontext_pushed.send(self.app, _async_wrapper=self.app.ensure_sync)

    def pop(self, exc: BaseException | None = _sentinel) -> None:  # type: ignore
        """Pops the app context."""
        try:
            if len(self._cv_tokens) == 1:
                if exc is _sentinel:
                    exc = sys.exc_info()[1]
                self.app.do_teardown_appcontext(exc)
        finally:
            ctx = _cv_app.get()
            _cv_app.reset(self._cv_tokens.pop())

        if ctx is not self:
            raise AssertionError(
                f"Popped wrong app context. ({ctx!r} instead of {self!r})"
            )

        appcontext_popped.send(self.app, _async_wrapper=self.app.ensure_sync)

    def __enter__(self) -> AppContext:
        self.push()
        return self

    def __exit__(
        self,
        exc_type: type | None,
        exc_value: BaseException | None,
        tb: TracebackType | None,
    ) -> None:
        self.pop(exc_value)


class RequestContext:
    """The request context contains per-request information. The Flask
    app creates and pushes it at the beginning of the request, then pops
    it at the end of the request. It will create the URL adapter and
    request object for the WSGI environment provided.

    Do not attempt to use this class directly, instead use
    :meth:`~flask.Flask.test_request_context` and
    :meth:`~flask.Flask.request_context` to create this object.

    When the request context is popped, it will evaluate all the
    functions registered on the application for teardown execution
    (:meth:`~flask.Flask.teardown_request`).

    The request context is automatically popped at the end of the
    request. When using the interactive debugger, the context will be
    restored so ``request`` is still accessible. Similarly, the test
    client can preserve the context after the request ends. However,
    teardown functions may already have closed some resources such as
    database connections.
    """

    def __init__(
        self,
        app: Flask,
        environ: WSGIEnvironment,
        request: Request | None = None,
        session: SessionMixin | None = None,
    ) -> None:
        self.app = app
        if request is None:
            request = app.request_class(environ)
            request.json_module = app.json
        self.request: Request = request
        self.url_adapter = None
        try:
            self.url_adapter = app.create_url_adapter(self.request)
        except HTTPException as e:
            self.request.routing_exception = e
        self.flashes: list[tuple[str, str]] | None = None
        self.session: SessionMixin | None = session
        # Functions that should be executed after the request on the response
        # object.  These will be called before the regular "after_request"
        # functions.
        self._after_request_functions: list[ft.AfterRequestCallable[t.Any]] = []

        self._cv_tokens: list[
            tuple[contextvars.Token[RequestContext], AppContext | None]
        ] = []

    def copy(self) -> RequestContext:
        """Creates a copy of this request context with the same request object.
        This can be used to move a request context to a different greenlet.
        Because the actual request object is the same this cannot be used to
        move a request context to a different thread unless access to the
        request object is locked.

        .. versionadded:: 0.10

        .. versionchanged:: 1.1
           The current session object is used instead of reloading the original
           data. This prevents `flask.session` pointing to an out-of-date object.
        """
        return self.__class__(
            self.app,
            environ=self.request.environ,
            request=self.request,
            session=self.session,
        )

    def match_request(self) -> None:
        """Can be overridden by a subclass to hook into the matching
        of the request.
        """
        try:
            result = self.url_adapter.match(return_rule=True)  # type: ignore
            self.request.url_rule, self.request.view_args = result  # type: ignore
        except HTTPException as e:
            self.request.routing_exception = e

    def push(self) -> None:
        # Before we push the request context we have to ensure that there
        # is an application context.
        app_ctx = _cv_app.get(None)

        if app_ctx is None or app_ctx.app is not self.app:
            app_ctx = self.app.app_context()
            app_ctx.push()
        else:
            app_ctx = None

        self._cv_tokens.append((_cv_request.set(self), app_ctx))

        # Open the session at the moment that the request context is available.
        # This allows a custom open_session method to use the request context.
        # Only open a new session if this is the first time the request was
        # pushed, otherwise stream_with_context loses the session.
        if self.session is None:
            session_interface = self.app.session_interface
            self.session = session_interface.open_session(self.app, self.request)

            if self.session is None:
                self.session = session_interface.make_null_session(self.app)

        # Match the request URL after loading the session, so that the
        # session is available in custom URL converters.
        if self.url_adapter is not None:
            self.match_request()

    def pop(self, exc: BaseException | None = _sentinel) -> None:  # type: ignore
        """Pops the request context and unbinds it by doing that.  This will
        also trigger the execution of functions registered by the
        :meth:`~flask.Flask.teardown_request` decorator.

        .. versionchanged:: 0.9
           Added the `exc` argument.
        """
        clear_request = len(self._cv_tokens) == 1

        try:
            if clear_request:
                if exc is _sentinel:
                    exc = sys.exc_info()[1]
                self.app.do_teardown_request(exc)

                request_close = getattr(self.request, "close", None)
                if request_close is not None:
                    request_close()
        finally:
            ctx = _cv_request.get()
            token, app_ctx = self._cv_tokens.pop()
            _cv_request.reset(token)

            # get rid of circular dependencies at the end of the request
            # so that we don't require the GC to be active.
            if clear_request:
                ctx.request.environ["werkzeug.request"] = None

            if app_ctx is not None:
                app_ctx.pop(exc)

            if ctx is not self:
                raise AssertionError(
                    f"Popped wrong request context. ({ctx!r} instead of {self!r})"
                )

    def __enter__(self) -> RequestContext:
        self.push()
        return self

    def __exit__(
        self,
        exc_type: type | None,
        exc_value: BaseException | None,
        tb: TracebackType | None,
    ) -> None:
        self.pop(exc_value)

    def __repr__(self) -> str:
        return (
            f"<{type(self).__name__} {self.request.url!r}"
            f" [{self.request.method}] of {self.app.name}>"
        )


Filepath: githubCode\src\flask\debughelpers.py:

from __future__ import annotations

import typing as t

from jinja2.loaders import BaseLoader
from werkzeug.routing import RequestRedirect

from .blueprints import Blueprint
from .globals import request_ctx
from .sansio.app import App

if t.TYPE_CHECKING:
    from .sansio.scaffold import Scaffold
    from .wrappers import Request


class UnexpectedUnicodeError(AssertionError, UnicodeError):
    """Raised in places where we want some better error reporting for
    unexpected unicode or binary data.
    """


class DebugFilesKeyError(KeyError, AssertionError):
    """Raised from request.files during debugging.  The idea is that it can
    provide a better error message than just a generic KeyError/BadRequest.
    """

    def __init__(self, request: Request, key: str) -> None:
        form_matches = request.form.getlist(key)
        buf = [
            f"You tried to access the file {key!r} in the request.files"
            " dictionary but it does not exist. The mimetype for the"
            f" request is {request.mimetype!r} instead of"
            " 'multipart/form-data' which means that no file contents"
            " were transmitted. To fix this error you should provide"
            ' enctype="multipart/form-data" in your form.'
        ]
        if form_matches:
            names = ", ".join(repr(x) for x in form_matches)
            buf.append(
                "\n\nThe browser instead transmitted some file names. "
                f"This was submitted: {names}"
            )
        self.msg = "".join(buf)

    def __str__(self) -> str:
        return self.msg


class FormDataRoutingRedirect(AssertionError):
    """This exception is raised in debug mode if a routing redirect
    would cause the browser to drop the method or body. This happens
    when method is not GET, HEAD or OPTIONS and the status code is not
    307 or 308.
    """

    def __init__(self, request: Request) -> None:
        exc = request.routing_exception
        assert isinstance(exc, RequestRedirect)
        buf = [
            f"A request was sent to '{request.url}', but routing issued"
            f" a redirect to the canonical URL '{exc.new_url}'."
        ]

        if f"{request.base_url}/" == exc.new_url.partition("?")[0]:
            buf.append(
                " The URL was defined with a trailing slash. Flask"
                " will redirect to the URL with a trailing slash if it"
                " was accessed without one."
            )

        buf.append(
            " Send requests to the canonical URL, or use 307 or 308 for"
            " routing redirects. Otherwise, browsers will drop form"
            " data.\n\n"
            "This exception is only raised in debug mode."
        )
        super().__init__("".join(buf))


def attach_enctype_error_multidict(request: Request) -> None:
    """Patch ``request.files.__getitem__`` to raise a descriptive error
    about ``enctype=multipart/form-data``.

    :param request: The request to patch.
    :meta private:
    """
    oldcls = request.files.__class__

    class newcls(oldcls):  # type: ignore[valid-type, misc]
        def __getitem__(self, key: str) -> t.Any:
            try:
                return super().__getitem__(key)
            except KeyError as e:
                if key not in request.form:
                    raise

                raise DebugFilesKeyError(request, key).with_traceback(
                    e.__traceback__
                ) from None

    newcls.__name__ = oldcls.__name__
    newcls.__module__ = oldcls.__module__
    request.files.__class__ = newcls


def _dump_loader_info(loader: BaseLoader) -> t.Iterator[str]:
    yield f"class: {type(loader).__module__}.{type(loader).__name__}"
    for key, value in sorted(loader.__dict__.items()):
        if key.startswith("_"):
            continue
        if isinstance(value, (tuple, list)):
            if not all(isinstance(x, str) for x in value):
                continue
            yield f"{key}:"
            for item in value:
                yield f"  - {item}"
            continue
        elif not isinstance(value, (str, int, float, bool)):
            continue
        yield f"{key}: {value!r}"


def explain_template_loading_attempts(
    app: App,
    template: str,
    attempts: list[
        tuple[
            BaseLoader,
            Scaffold,
            tuple[str, str | None, t.Callable[[], bool] | None] | None,
        ]
    ],
) -> None:
    """This should help developers understand what failed"""
    info = [f"Locating template {template!r}:"]
    total_found = 0
    blueprint = None
    if request_ctx and request_ctx.request.blueprint is not None:
        blueprint = request_ctx.request.blueprint

    for idx, (loader, srcobj, triple) in enumerate(attempts):
        if isinstance(srcobj, App):
            src_info = f"application {srcobj.import_name!r}"
        elif isinstance(srcobj, Blueprint):
            src_info = f"blueprint {srcobj.name!r} ({srcobj.import_name})"
        else:
            src_info = repr(srcobj)

        info.append(f"{idx + 1:5}: trying loader of {src_info}")

        for line in _dump_loader_info(loader):
            info.append(f"       {line}")

        if triple is None:
            detail = "no match"
        else:
            detail = f"found ({triple[1] or '<string>'!r})"
            total_found += 1
        info.append(f"       -> {detail}")

    seems_fishy = False
    if total_found == 0:
        info.append("Error: the template could not be found.")
        seems_fishy = True
    elif total_found > 1:
        info.append("Warning: multiple loaders returned a match for the template.")
        seems_fishy = True

    if blueprint is not None and seems_fishy:
        info.append(
            "  The template was looked up from an endpoint that belongs"
            f" to the blueprint {blueprint!r}."
        )
        info.append("  Maybe you did not place a template in the right folder?")
        info.append("  See https://flask.palletsprojects.com/blueprints/#templates")

    app.logger.info("\n".join(info))


Filepath: githubCode\src\flask\globals.py:

from __future__ import annotations

import typing as t
from contextvars import ContextVar

from werkzeug.local import LocalProxy

if t.TYPE_CHECKING:  # pragma: no cover
    from .app import Flask
    from .ctx import _AppCtxGlobals
    from .ctx import AppContext
    from .ctx import RequestContext
    from .sessions import SessionMixin
    from .wrappers import Request


_no_app_msg = """\
Working outside of application context.

This typically means that you attempted to use functionality that needed
the current application. To solve this, set up an application context
with app.app_context(). See the documentation for more information.\
"""
_cv_app: ContextVar[AppContext] = ContextVar("flask.app_ctx")
app_ctx: AppContext = LocalProxy(  # type: ignore[assignment]
    _cv_app, unbound_message=_no_app_msg
)
current_app: Flask = LocalProxy(  # type: ignore[assignment]
    _cv_app, "app", unbound_message=_no_app_msg
)
g: _AppCtxGlobals = LocalProxy(  # type: ignore[assignment]
    _cv_app, "g", unbound_message=_no_app_msg
)

_no_req_msg = """\
Working outside of request context.

This typically means that you attempted to use functionality that needed
an active HTTP request. Consult the documentation on testing for
information about how to avoid this problem.\
"""
_cv_request: ContextVar[RequestContext] = ContextVar("flask.request_ctx")
request_ctx: RequestContext = LocalProxy(  # type: ignore[assignment]
    _cv_request, unbound_message=_no_req_msg
)
request: Request = LocalProxy(  # type: ignore[assignment]
    _cv_request, "request", unbound_message=_no_req_msg
)
session: SessionMixin = LocalProxy(  # type: ignore[assignment]
    _cv_request, "session", unbound_message=_no_req_msg
)


Filepath: githubCode\src\flask\helpers.py:

from __future__ import annotations

import importlib.util
import os
import sys
import typing as t
from datetime import datetime
from functools import lru_cache
from functools import update_wrapper

import werkzeug.utils
from werkzeug.exceptions import abort as _wz_abort
from werkzeug.utils import redirect as _wz_redirect
from werkzeug.wrappers import Response as BaseResponse

from .globals import _cv_request
from .globals import current_app
from .globals import request
from .globals import request_ctx
from .globals import session
from .signals import message_flashed

if t.TYPE_CHECKING:  # pragma: no cover
    from .wrappers import Response


def get_debug_flag() -> bool:
    """Get whether debug mode should be enabled for the app, indicated by the
    :envvar:`FLASK_DEBUG` environment variable. The default is ``False``.
    """
    val = os.environ.get("FLASK_DEBUG")
    return bool(val and val.lower() not in {"0", "false", "no"})


def get_load_dotenv(default: bool = True) -> bool:
    """Get whether the user has disabled loading default dotenv files by
    setting :envvar:`FLASK_SKIP_DOTENV`. The default is ``True``, load
    the files.

    :param default: What to return if the env var isn't set.
    """
    val = os.environ.get("FLASK_SKIP_DOTENV")

    if not val:
        return default

    return val.lower() in ("0", "false", "no")


def stream_with_context(
    generator_or_function: t.Iterator[t.AnyStr] | t.Callable[..., t.Iterator[t.AnyStr]],
) -> t.Iterator[t.AnyStr]:
    """Request contexts disappear when the response is started on the server.
    This is done for efficiency reasons and to make it less likely to encounter
    memory leaks with badly written WSGI middlewares.  The downside is that if
    you are using streamed responses, the generator cannot access request bound
    information any more.

    This function however can help you keep the context around for longer::

        from flask import stream_with_context, request, Response

        @app.route('/stream')
        def streamed_response():
            @stream_with_context
            def generate():
                yield 'Hello '
                yield request.args['name']
                yield '!'
            return Response(generate())

    Alternatively it can also be used around a specific generator::

        from flask import stream_with_context, request, Response

        @app.route('/stream')
        def streamed_response():
            def generate():
                yield 'Hello '
                yield request.args['name']
                yield '!'
            return Response(stream_with_context(generate()))

    .. versionadded:: 0.9
    """
    try:
        gen = iter(generator_or_function)  # type: ignore[arg-type]
    except TypeError:

        def decorator(*args: t.Any, **kwargs: t.Any) -> t.Any:
            gen = generator_or_function(*args, **kwargs)  # type: ignore[operator]
            return stream_with_context(gen)

        return update_wrapper(decorator, generator_or_function)  # type: ignore[arg-type]

    def generator() -> t.Iterator[t.AnyStr | None]:
        ctx = _cv_request.get(None)
        if ctx is None:
            raise RuntimeError(
                "'stream_with_context' can only be used when a request"
                " context is active, such as in a view function."
            )
        with ctx:
            # Dummy sentinel.  Has to be inside the context block or we're
            # not actually keeping the context around.
            yield None

            # The try/finally is here so that if someone passes a WSGI level
            # iterator in we're still running the cleanup logic.  Generators
            # don't need that because they are closed on their destruction
            # automatically.
            try:
                yield from gen
            finally:
                if hasattr(gen, "close"):
                    gen.close()

    # The trick is to start the generator.  Then the code execution runs until
    # the first dummy None is yielded at which point the context was already
    # pushed.  This item is discarded.  Then when the iteration continues the
    # real generator is executed.
    wrapped_g = generator()
    next(wrapped_g)
    return wrapped_g  # type: ignore[return-value]


def make_response(*args: t.Any) -> Response:
    """Sometimes it is necessary to set additional headers in a view.  Because
    views do not have to return response objects but can return a value that
    is converted into a response object by Flask itself, it becomes tricky to
    add headers to it.  This function can be called instead of using a return
    and you will get a response object which you can use to attach headers.

    If view looked like this and you want to add a new header::

        def index():
            return render_template('index.html', foo=42)

    You can now do something like this::

        def index():
            response = make_response(render_template('index.html', foo=42))
            response.headers['X-Parachutes'] = 'parachutes are cool'
            return response

    This function accepts the very same arguments you can return from a
    view function.  This for example creates a response with a 404 error
    code::

        response = make_response(render_template('not_found.html'), 404)

    The other use case of this function is to force the return value of a
    view function into a response which is helpful with view
    decorators::

        response = make_response(view_function())
        response.headers['X-Parachutes'] = 'parachutes are cool'

    Internally this function does the following things:

    -   if no arguments are passed, it creates a new response argument
    -   if one argument is passed, :meth:`flask.Flask.make_response`
        is invoked with it.
    -   if more than one argument is passed, the arguments are passed
        to the :meth:`flask.Flask.make_response` function as tuple.

    .. versionadded:: 0.6
    """
    if not args:
        return current_app.response_class()
    if len(args) == 1:
        args = args[0]
    return current_app.make_response(args)


def url_for(
    endpoint: str,
    *,
    _anchor: str | None = None,
    _method: str | None = None,
    _scheme: str | None = None,
    _external: bool | None = None,
    **values: t.Any,
) -> str:
    """Generate a URL to the given endpoint with the given values.

    This requires an active request or application context, and calls
    :meth:`current_app.url_for() <flask.Flask.url_for>`. See that method
    for full documentation.

    :param endpoint: The endpoint name associated with the URL to
        generate. If this starts with a ``.``, the current blueprint
        name (if any) will be used.
    :param _anchor: If given, append this as ``#anchor`` to the URL.
    :param _method: If given, generate the URL associated with this
        method for the endpoint.
    :param _scheme: If given, the URL will have this scheme if it is
        external.
    :param _external: If given, prefer the URL to be internal (False) or
        require it to be external (True). External URLs include the
        scheme and domain. When not in an active request, URLs are
        external by default.
    :param values: Values to use for the variable parts of the URL rule.
        Unknown keys are appended as query string arguments, like
        ``?a=b&c=d``.

    .. versionchanged:: 2.2
        Calls ``current_app.url_for``, allowing an app to override the
        behavior.

    .. versionchanged:: 0.10
       The ``_scheme`` parameter was added.

    .. versionchanged:: 0.9
       The ``_anchor`` and ``_method`` parameters were added.

    .. versionchanged:: 0.9
       Calls ``app.handle_url_build_error`` on build errors.
    """
    return current_app.url_for(
        endpoint,
        _anchor=_anchor,
        _method=_method,
        _scheme=_scheme,
        _external=_external,
        **values,
    )


def redirect(
    location: str, code: int = 302, Response: type[BaseResponse] | None = None
) -> BaseResponse:
    """Create a redirect response object.

    If :data:`~flask.current_app` is available, it will use its
    :meth:`~flask.Flask.redirect` method, otherwise it will use
    :func:`werkzeug.utils.redirect`.

    :param location: The URL to redirect to.
    :param code: The status code for the redirect.
    :param Response: The response class to use. Not used when
        ``current_app`` is active, which uses ``app.response_class``.

    .. versionadded:: 2.2
        Calls ``current_app.redirect`` if available instead of always
        using Werkzeug's default ``redirect``.
    """
    if current_app:
        return current_app.redirect(location, code=code)

    return _wz_redirect(location, code=code, Response=Response)


def abort(code: int | BaseResponse, *args: t.Any, **kwargs: t.Any) -> t.NoReturn:
    """Raise an :exc:`~werkzeug.exceptions.HTTPException` for the given
    status code.

    If :data:`~flask.current_app` is available, it will call its
    :attr:`~flask.Flask.aborter` object, otherwise it will use
    :func:`werkzeug.exceptions.abort`.

    :param code: The status code for the exception, which must be
        registered in ``app.aborter``.
    :param args: Passed to the exception.
    :param kwargs: Passed to the exception.

    .. versionadded:: 2.2
        Calls ``current_app.aborter`` if available instead of always
        using Werkzeug's default ``abort``.
    """
    if current_app:
        current_app.aborter(code, *args, **kwargs)

    _wz_abort(code, *args, **kwargs)


def get_template_attribute(template_name: str, attribute: str) -> t.Any:
    """Loads a macro (or variable) a template exports.  This can be used to
    invoke a macro from within Python code.  If you for example have a
    template named :file:`_cider.html` with the following contents:

    .. sourcecode:: html+jinja

       {% macro hello(name) %}Hello {{ name }}!{% endmacro %}

    You can access this from Python code like this::

        hello = get_template_attribute('_cider.html', 'hello')
        return hello('World')

    .. versionadded:: 0.2

    :param template_name: the name of the template
    :param attribute: the name of the variable of macro to access
    """
    return getattr(current_app.jinja_env.get_template(template_name).module, attribute)


def flash(message: str, category: str = "message") -> None:
    """Flashes a message to the next request.  In order to remove the
    flashed message from the session and to display it to the user,
    the template has to call :func:`get_flashed_messages`.

    .. versionchanged:: 0.3
       `category` parameter added.

    :param message: the message to be flashed.
    :param category: the category for the message.  The following values
                     are recommended: ``'message'`` for any kind of message,
                     ``'error'`` for errors, ``'info'`` for information
                     messages and ``'warning'`` for warnings.  However any
                     kind of string can be used as category.
    """
    # Original implementation:
    #
    #     session.setdefault('_flashes', []).append((category, message))
    #
    # This assumed that changes made to mutable structures in the session are
    # always in sync with the session object, which is not true for session
    # implementations that use external storage for keeping their keys/values.
    flashes = session.get("_flashes", [])
    flashes.append((category, message))
    session["_flashes"] = flashes
    app = current_app._get_current_object()  # type: ignore
    message_flashed.send(
        app,
        _async_wrapper=app.ensure_sync,
        message=message,
        category=category,
    )


def get_flashed_messages(
    with_categories: bool = False, category_filter: t.Iterable[str] = ()
) -> list[str] | list[tuple[str, str]]:
    """Pulls all flashed messages from the session and returns them.
    Further calls in the same request to the function will return
    the same messages.  By default just the messages are returned,
    but when `with_categories` is set to ``True``, the return value will
    be a list of tuples in the form ``(category, message)`` instead.

    Filter the flashed messages to one or more categories by providing those
    categories in `category_filter`.  This allows rendering categories in
    separate html blocks.  The `with_categories` and `category_filter`
    arguments are distinct:

    * `with_categories` controls whether categories are returned with message
      text (``True`` gives a tuple, where ``False`` gives just the message text).
    * `category_filter` filters the messages down to only those matching the
      provided categories.

    See :doc:`/patterns/flashing` for examples.

    .. versionchanged:: 0.3
       `with_categories` parameter added.

    .. versionchanged:: 0.9
        `category_filter` parameter added.

    :param with_categories: set to ``True`` to also receive categories.
    :param category_filter: filter of categories to limit return values.  Only
                            categories in the list will be returned.
    """
    flashes = request_ctx.flashes
    if flashes is None:
        flashes = session.pop("_flashes") if "_flashes" in session else []
        request_ctx.flashes = flashes
    if category_filter:
        flashes = list(filter(lambda f: f[0] in category_filter, flashes))
    if not with_categories:
        return [x[1] for x in flashes]
    return flashes


def _prepare_send_file_kwargs(**kwargs: t.Any) -> dict[str, t.Any]:
    if kwargs.get("max_age") is None:
        kwargs["max_age"] = current_app.get_send_file_max_age

    kwargs.update(
        environ=request.environ,
        use_x_sendfile=current_app.config["USE_X_SENDFILE"],
        response_class=current_app.response_class,
        _root_path=current_app.root_path,  # type: ignore
    )
    return kwargs


def send_file(
    path_or_file: os.PathLike[t.AnyStr] | str | t.BinaryIO,
    mimetype: str | None = None,
    as_attachment: bool = False,
    download_name: str | None = None,
    conditional: bool = True,
    etag: bool | str = True,
    last_modified: datetime | int | float | None = None,
    max_age: None | (int | t.Callable[[str | None], int | None]) = None,
) -> Response:
    """Send the contents of a file to the client.

    The first argument can be a file path or a file-like object. Paths
    are preferred in most cases because Werkzeug can manage the file and
    get extra information from the path. Passing a file-like object
    requires that the file is opened in binary mode, and is mostly
    useful when building a file in memory with :class:`io.BytesIO`.

    Never pass file paths provided by a user. The path is assumed to be
    trusted, so a user could craft a path to access a file you didn't
    intend. Use :func:`send_from_directory` to safely serve
    user-requested paths from within a directory.

    If the WSGI server sets a ``file_wrapper`` in ``environ``, it is
    used, otherwise Werkzeug's built-in wrapper is used. Alternatively,
    if the HTTP server supports ``X-Sendfile``, configuring Flask with
    ``USE_X_SENDFILE = True`` will tell the server to send the given
    path, which is much more efficient than reading it in Python.

    :param path_or_file: The path to the file to send, relative to the
        current working directory if a relative path is given.
        Alternatively, a file-like object opened in binary mode. Make
        sure the file pointer is seeked to the start of the data.
    :param mimetype: The MIME type to send for the file. If not
        provided, it will try to detect it from the file name.
    :param as_attachment: Indicate to a browser that it should offer to
        save the file instead of displaying it.
    :param download_name: The default name browsers will use when saving
        the file. Defaults to the passed file name.
    :param conditional: Enable conditional and range responses based on
        request headers. Requires passing a file path and ``environ``.
    :param etag: Calculate an ETag for the file, which requires passing
        a file path. Can also be a string to use instead.
    :param last_modified: The last modified time to send for the file,
        in seconds. If not provided, it will try to detect it from the
        file path.
    :param max_age: How long the client should cache the file, in
        seconds. If set, ``Cache-Control`` will be ``public``, otherwise
        it will be ``no-cache`` to prefer conditional caching.

    .. versionchanged:: 2.0
        ``download_name`` replaces the ``attachment_filename``
        parameter. If ``as_attachment=False``, it is passed with
        ``Content-Disposition: inline`` instead.

    .. versionchanged:: 2.0
        ``max_age`` replaces the ``cache_timeout`` parameter.
        ``conditional`` is enabled and ``max_age`` is not set by
        default.

    .. versionchanged:: 2.0
        ``etag`` replaces the ``add_etags`` parameter. It can be a
        string to use instead of generating one.

    .. versionchanged:: 2.0
        Passing a file-like object that inherits from
        :class:`~io.TextIOBase` will raise a :exc:`ValueError` rather
        than sending an empty file.

    .. versionadded:: 2.0
        Moved the implementation to Werkzeug. This is now a wrapper to
        pass some Flask-specific arguments.

    .. versionchanged:: 1.1
        ``filename`` may be a :class:`~os.PathLike` object.

    .. versionchanged:: 1.1
        Passing a :class:`~io.BytesIO` object supports range requests.

    .. versionchanged:: 1.0.3
        Filenames are encoded with ASCII instead of Latin-1 for broader
        compatibility with WSGI servers.

    .. versionchanged:: 1.0
        UTF-8 filenames as specified in :rfc:`2231` are supported.

    .. versionchanged:: 0.12
        The filename is no longer automatically inferred from file
        objects. If you want to use automatic MIME and etag support,
        pass a filename via ``filename_or_fp`` or
        ``attachment_filename``.

    .. versionchanged:: 0.12
        ``attachment_filename`` is preferred over ``filename`` for MIME
        detection.

    .. versionchanged:: 0.9
        ``cache_timeout`` defaults to
        :meth:`Flask.get_send_file_max_age`.

    .. versionchanged:: 0.7
        MIME guessing and etag support for file-like objects was
        removed because it was unreliable. Pass a filename if you are
        able to, otherwise attach an etag yourself.

    .. versionchanged:: 0.5
        The ``add_etags``, ``cache_timeout`` and ``conditional``
        parameters were added. The default behavior is to add etags.

    .. versionadded:: 0.2
    """
    return werkzeug.utils.send_file(  # type: ignore[return-value]
        **_prepare_send_file_kwargs(
            path_or_file=path_or_file,
            environ=request.environ,
            mimetype=mimetype,
            as_attachment=as_attachment,
            download_name=download_name,
            conditional=conditional,
            etag=etag,
            last_modified=last_modified,
            max_age=max_age,
        )
    )


def send_from_directory(
    directory: os.PathLike[str] | str,
    path: os.PathLike[str] | str,
    **kwargs: t.Any,
) -> Response:
    """Send a file from within a directory using :func:`send_file`.

    .. code-block:: python

        @app.route("/uploads/<path:name>")
        def download_file(name):
            return send_from_directory(
                app.config['UPLOAD_FOLDER'], name, as_attachment=True
            )

    This is a secure way to serve files from a folder, such as static
    files or uploads. Uses :func:`~werkzeug.security.safe_join` to
    ensure the path coming from the client is not maliciously crafted to
    point outside the specified directory.

    If the final path does not point to an existing regular file,
    raises a 404 :exc:`~werkzeug.exceptions.NotFound` error.

    :param directory: The directory that ``path`` must be located under,
        relative to the current application's root path.
    :param path: The path to the file to send, relative to
        ``directory``.
    :param kwargs: Arguments to pass to :func:`send_file`.

    .. versionchanged:: 2.0
        ``path`` replaces the ``filename`` parameter.

    .. versionadded:: 2.0
        Moved the implementation to Werkzeug. This is now a wrapper to
        pass some Flask-specific arguments.

    .. versionadded:: 0.5
    """
    return werkzeug.utils.send_from_directory(  # type: ignore[return-value]
        directory, path, **_prepare_send_file_kwargs(**kwargs)
    )


def get_root_path(import_name: str) -> str:
    """Find the root path of a package, or the path that contains a
    module. If it cannot be found, returns the current working
    directory.

    Not to be confused with the value returned by :func:`find_package`.

    :meta private:
    """
    # Module already imported and has a file attribute. Use that first.
    mod = sys.modules.get(import_name)

    if mod is not None and hasattr(mod, "__file__") and mod.__file__ is not None:
        return os.path.dirname(os.path.abspath(mod.__file__))

    # Next attempt: check the loader.
    try:
        spec = importlib.util.find_spec(import_name)

        if spec is None:
            raise ValueError
    except (ImportError, ValueError):
        loader = None
    else:
        loader = spec.loader

    # Loader does not exist or we're referring to an unloaded main
    # module or a main module without path (interactive sessions), go
    # with the current working directory.
    if loader is None:
        return os.getcwd()

    if hasattr(loader, "get_filename"):
        filepath = loader.get_filename(import_name)
    else:
        # Fall back to imports.
        __import__(import_name)
        mod = sys.modules[import_name]
        filepath = getattr(mod, "__file__", None)

        # If we don't have a file path it might be because it is a
        # namespace package. In this case pick the root path from the
        # first module that is contained in the package.
        if filepath is None:
            raise RuntimeError(
                "No root path can be found for the provided module"
                f" {import_name!r}. This can happen because the module"
                " came from an import hook that does not provide file"
                " name information or because it's a namespace package."
                " In this case the root path needs to be explicitly"
                " provided."
            )

    # filepath is import_name.py for a module, or __init__.py for a package.
    return os.path.dirname(os.path.abspath(filepath))  # type: ignore[no-any-return]


@lru_cache(maxsize=None)
def _split_blueprint_path(name: str) -> list[str]:
    out: list[str] = [name]

    if "." in name:
        out.extend(_split_blueprint_path(name.rpartition(".")[0]))

    return out


Filepath: githubCode\src\flask\logging.py:

from __future__ import annotations

import logging
import sys
import typing as t

from werkzeug.local import LocalProxy

from .globals import request

if t.TYPE_CHECKING:  # pragma: no cover
    from .sansio.app import App


@LocalProxy
def wsgi_errors_stream() -> t.TextIO:
    """Find the most appropriate error stream for the application. If a request
    is active, log to ``wsgi.errors``, otherwise use ``sys.stderr``.

    If you configure your own :class:`logging.StreamHandler`, you may want to
    use this for the stream. If you are using file or dict configuration and
    can't import this directly, you can refer to it as
    ``ext://flask.logging.wsgi_errors_stream``.
    """
    if request:
        return request.environ["wsgi.errors"]  # type: ignore[no-any-return]

    return sys.stderr


def has_level_handler(logger: logging.Logger) -> bool:
    """Check if there is a handler in the logging chain that will handle the
    given logger's :meth:`effective level <~logging.Logger.getEffectiveLevel>`.
    """
    level = logger.getEffectiveLevel()
    current = logger

    while current:
        if any(handler.level <= level for handler in current.handlers):
            return True

        if not current.propagate:
            break

        current = current.parent  # type: ignore

    return False


#: Log messages to :func:`~flask.logging.wsgi_errors_stream` with the format
#: ``[%(asctime)s] %(levelname)s in %(module)s: %(message)s``.
default_handler = logging.StreamHandler(wsgi_errors_stream)  # type: ignore
default_handler.setFormatter(
    logging.Formatter("[%(asctime)s] %(levelname)s in %(module)s: %(message)s")
)


def create_logger(app: App) -> logging.Logger:
    """Get the Flask app's logger and configure it if needed.

    The logger name will be the same as
    :attr:`app.import_name <flask.Flask.name>`.

    When :attr:`~flask.Flask.debug` is enabled, set the logger level to
    :data:`logging.DEBUG` if it is not set.

    If there is no handler for the logger's effective level, add a
    :class:`~logging.StreamHandler` for
    :func:`~flask.logging.wsgi_errors_stream` with a basic format.
    """
    logger = logging.getLogger(app.name)

    if app.debug and not logger.level:
        logger.setLevel(logging.DEBUG)

    if not has_level_handler(logger):
        logger.addHandler(default_handler)

    return logger


Filepath: githubCode\src\flask\sessions.py:

from __future__ import annotations

import hashlib
import typing as t
from collections.abc import MutableMapping
from datetime import datetime
from datetime import timezone

from itsdangerous import BadSignature
from itsdangerous import URLSafeTimedSerializer
from werkzeug.datastructures import CallbackDict

from .json.tag import TaggedJSONSerializer

if t.TYPE_CHECKING:  # pragma: no cover
    import typing_extensions as te

    from .app import Flask
    from .wrappers import Request
    from .wrappers import Response


# TODO generic when Python > 3.8
class SessionMixin(MutableMapping):  # type: ignore[type-arg]
    """Expands a basic dictionary with session attributes."""

    @property
    def permanent(self) -> bool:
        """This reflects the ``'_permanent'`` key in the dict."""
        return self.get("_permanent", False)

    @permanent.setter
    def permanent(self, value: bool) -> None:
        self["_permanent"] = bool(value)

    #: Some implementations can detect whether a session is newly
    #: created, but that is not guaranteed. Use with caution. The mixin
    # default is hard-coded ``False``.
    new = False

    #: Some implementations can detect changes to the session and set
    #: this when that happens. The mixin default is hard coded to
    #: ``True``.
    modified = True

    #: Some implementations can detect when session data is read or
    #: written and set this when that happens. The mixin default is hard
    #: coded to ``True``.
    accessed = True


# TODO generic when Python > 3.8
class SecureCookieSession(CallbackDict, SessionMixin):  # type: ignore[type-arg]
    """Base class for sessions based on signed cookies.

    This session backend will set the :attr:`modified` and
    :attr:`accessed` attributes. It cannot reliably track whether a
    session is new (vs. empty), so :attr:`new` remains hard coded to
    ``False``.
    """

    #: When data is changed, this is set to ``True``. Only the session
    #: dictionary itself is tracked; if the session contains mutable
    #: data (for example a nested dict) then this must be set to
    #: ``True`` manually when modifying that data. The session cookie
    #: will only be written to the response if this is ``True``.
    modified = False

    #: When data is read or written, this is set to ``True``. Used by
    # :class:`.SecureCookieSessionInterface` to add a ``Vary: Cookie``
    #: header, which allows caching proxies to cache different pages for
    #: different users.
    accessed = False

    def __init__(self, initial: t.Any = None) -> None:
        def on_update(self: te.Self) -> None:
            self.modified = True
            self.accessed = True

        super().__init__(initial, on_update)

    def __getitem__(self, key: str) -> t.Any:
        self.accessed = True
        return super().__getitem__(key)

    def get(self, key: str, default: t.Any = None) -> t.Any:
        self.accessed = True
        return super().get(key, default)

    def setdefault(self, key: str, default: t.Any = None) -> t.Any:
        self.accessed = True
        return super().setdefault(key, default)


class NullSession(SecureCookieSession):
    """Class used to generate nicer error messages if sessions are not
    available.  Will still allow read-only access to the empty session
    but fail on setting.
    """

    def _fail(self, *args: t.Any, **kwargs: t.Any) -> t.NoReturn:
        raise RuntimeError(
            "The session is unavailable because no secret "
            "key was set.  Set the secret_key on the "
            "application to something unique and secret."
        )

    __setitem__ = __delitem__ = clear = pop = popitem = update = setdefault = _fail  # type: ignore # noqa: B950
    del _fail


class SessionInterface:
    """The basic interface you have to implement in order to replace the
    default session interface which uses werkzeug's securecookie
    implementation.  The only methods you have to implement are
    :meth:`open_session` and :meth:`save_session`, the others have
    useful defaults which you don't need to change.

    The session object returned by the :meth:`open_session` method has to
    provide a dictionary like interface plus the properties and methods
    from the :class:`SessionMixin`.  We recommend just subclassing a dict
    and adding that mixin::

        class Session(dict, SessionMixin):
            pass

    If :meth:`open_session` returns ``None`` Flask will call into
    :meth:`make_null_session` to create a session that acts as replacement
    if the session support cannot work because some requirement is not
    fulfilled.  The default :class:`NullSession` class that is created
    will complain that the secret key was not set.

    To replace the session interface on an application all you have to do
    is to assign :attr:`flask.Flask.session_interface`::

        app = Flask(__name__)
        app.session_interface = MySessionInterface()

    Multiple requests with the same session may be sent and handled
    concurrently. When implementing a new session interface, consider
    whether reads or writes to the backing store must be synchronized.
    There is no guarantee on the order in which the session for each
    request is opened or saved, it will occur in the order that requests
    begin and end processing.

    .. versionadded:: 0.8
    """

    #: :meth:`make_null_session` will look here for the class that should
    #: be created when a null session is requested.  Likewise the
    #: :meth:`is_null_session` method will perform a typecheck against
    #: this type.
    null_session_class = NullSession

    #: A flag that indicates if the session interface is pickle based.
    #: This can be used by Flask extensions to make a decision in regards
    #: to how to deal with the session object.
    #:
    #: .. versionadded:: 0.10
    pickle_based = False

    def make_null_session(self, app: Flask) -> NullSession:
        """Creates a null session which acts as a replacement object if the
        real session support could not be loaded due to a configuration
        error.  This mainly aids the user experience because the job of the
        null session is to still support lookup without complaining but
        modifications are answered with a helpful error message of what
        failed.

        This creates an instance of :attr:`null_session_class` by default.
        """
        return self.null_session_class()

    def is_null_session(self, obj: object) -> bool:
        """Checks if a given object is a null session.  Null sessions are
        not asked to be saved.

        This checks if the object is an instance of :attr:`null_session_class`
        by default.
        """
        return isinstance(obj, self.null_session_class)

    def get_cookie_name(self, app: Flask) -> str:
        """The name of the session cookie. Uses``app.config["SESSION_COOKIE_NAME"]``."""
        return app.config["SESSION_COOKIE_NAME"]  # type: ignore[no-any-return]

    def get_cookie_domain(self, app: Flask) -> str | None:
        """The value of the ``Domain`` parameter on the session cookie. If not set,
        browsers will only send the cookie to the exact domain it was set from.
        Otherwise, they will send it to any subdomain of the given value as well.

        Uses the :data:`SESSION_COOKIE_DOMAIN` config.

        .. versionchanged:: 2.3
            Not set by default, does not fall back to ``SERVER_NAME``.
        """
        return app.config["SESSION_COOKIE_DOMAIN"]  # type: ignore[no-any-return]

    def get_cookie_path(self, app: Flask) -> str:
        """Returns the path for which the cookie should be valid.  The
        default implementation uses the value from the ``SESSION_COOKIE_PATH``
        config var if it's set, and falls back to ``APPLICATION_ROOT`` or
        uses ``/`` if it's ``None``.
        """
        return app.config["SESSION_COOKIE_PATH"] or app.config["APPLICATION_ROOT"]  # type: ignore[no-any-return]

    def get_cookie_httponly(self, app: Flask) -> bool:
        """Returns True if the session cookie should be httponly.  This
        currently just returns the value of the ``SESSION_COOKIE_HTTPONLY``
        config var.
        """
        return app.config["SESSION_COOKIE_HTTPONLY"]  # type: ignore[no-any-return]

    def get_cookie_secure(self, app: Flask) -> bool:
        """Returns True if the cookie should be secure.  This currently
        just returns the value of the ``SESSION_COOKIE_SECURE`` setting.
        """
        return app.config["SESSION_COOKIE_SECURE"]  # type: ignore[no-any-return]

    def get_cookie_samesite(self, app: Flask) -> str | None:
        """Return ``'Strict'`` or ``'Lax'`` if the cookie should use the
        ``SameSite`` attribute. This currently just returns the value of
        the :data:`SESSION_COOKIE_SAMESITE` setting.
        """
        return app.config["SESSION_COOKIE_SAMESITE"]  # type: ignore[no-any-return]

    def get_expiration_time(self, app: Flask, session: SessionMixin) -> datetime | None:
        """A helper method that returns an expiration date for the session
        or ``None`` if the session is linked to the browser session.  The
        default implementation returns now + the permanent session
        lifetime configured on the application.
        """
        if session.permanent:
            return datetime.now(timezone.utc) + app.permanent_session_lifetime
        return None

    def should_set_cookie(self, app: Flask, session: SessionMixin) -> bool:
        """Used by session backends to determine if a ``Set-Cookie`` header
        should be set for this session cookie for this response. If the session
        has been modified, the cookie is set. If the session is permanent and
        the ``SESSION_REFRESH_EACH_REQUEST`` config is true, the cookie is
        always set.

        This check is usually skipped if the session was deleted.

        .. versionadded:: 0.11
        """

        return session.modified or (
            session.permanent and app.config["SESSION_REFRESH_EACH_REQUEST"]
        )

    def open_session(self, app: Flask, request: Request) -> SessionMixin | None:
        """This is called at the beginning of each request, after
        pushing the request context, before matching the URL.

        This must return an object which implements a dictionary-like
        interface as well as the :class:`SessionMixin` interface.

        This will return ``None`` to indicate that loading failed in
        some way that is not immediately an error. The request
        context will fall back to using :meth:`make_null_session`
        in this case.
        """
        raise NotImplementedError()

    def save_session(
        self, app: Flask, session: SessionMixin, response: Response
    ) -> None:
        """This is called at the end of each request, after generating
        a response, before removing the request context. It is skipped
        if :meth:`is_null_session` returns ``True``.
        """
        raise NotImplementedError()


session_json_serializer = TaggedJSONSerializer()


class SecureCookieSessionInterface(SessionInterface):
    """The default session interface that stores sessions in signed cookies
    through the :mod:`itsdangerous` module.
    """

    #: the salt that should be applied on top of the secret key for the
    #: signing of cookie based sessions.
    salt = "cookie-session"
    #: the hash function to use for the signature.  The default is sha1
    digest_method = staticmethod(hashlib.sha1)
    #: the name of the itsdangerous supported key derivation.  The default
    #: is hmac.
    key_derivation = "hmac"
    #: A python serializer for the payload.  The default is a compact
    #: JSON derived serializer with support for some extra Python types
    #: such as datetime objects or tuples.
    serializer = session_json_serializer
    session_class = SecureCookieSession

    def get_signing_serializer(self, app: Flask) -> URLSafeTimedSerializer | None:
        if not app.secret_key:
            return None
        signer_kwargs = dict(
            key_derivation=self.key_derivation, digest_method=self.digest_method
        )
        return URLSafeTimedSerializer(
            app.secret_key,
            salt=self.salt,
            serializer=self.serializer,
            signer_kwargs=signer_kwargs,
        )

    def open_session(self, app: Flask, request: Request) -> SecureCookieSession | None:
        s = self.get_signing_serializer(app)
        if s is None:
            return None
        val = request.cookies.get(self.get_cookie_name(app))
        if not val:
            return self.session_class()
        max_age = int(app.permanent_session_lifetime.total_seconds())
        try:
            data = s.loads(val, max_age=max_age)
            return self.session_class(data)
        except BadSignature:
            return self.session_class()

    def save_session(
        self, app: Flask, session: SessionMixin, response: Response
    ) -> None:
        name = self.get_cookie_name(app)
        domain = self.get_cookie_domain(app)
        path = self.get_cookie_path(app)
        secure = self.get_cookie_secure(app)
        samesite = self.get_cookie_samesite(app)
        httponly = self.get_cookie_httponly(app)

        # Add a "Vary: Cookie" header if the session was accessed at all.
        if session.accessed:
            response.vary.add("Cookie")

        # If the session is modified to be empty, remove the cookie.
        # If the session is empty, return without setting the cookie.
        if not session:
            if session.modified:
                response.delete_cookie(
                    name,
                    domain=domain,
                    path=path,
                    secure=secure,
                    samesite=samesite,
                    httponly=httponly,
                )
                response.vary.add("Cookie")

            return

        if not self.should_set_cookie(app, session):
            return

        expires = self.get_expiration_time(app, session)
        val = self.get_signing_serializer(app).dumps(dict(session))  # type: ignore
        response.set_cookie(
            name,
            val,  # type: ignore
            expires=expires,
            httponly=httponly,
            domain=domain,
            path=path,
            secure=secure,
            samesite=samesite,
        )
        response.vary.add("Cookie")


Filepath: githubCode\src\flask\signals.py:

from __future__ import annotations

from blinker import Namespace

# This namespace is only for signals provided by Flask itself.
_signals = Namespace()

template_rendered = _signals.signal("template-rendered")
before_render_template = _signals.signal("before-render-template")
request_started = _signals.signal("request-started")
request_finished = _signals.signal("request-finished")
request_tearing_down = _signals.signal("request-tearing-down")
got_request_exception = _signals.signal("got-request-exception")
appcontext_tearing_down = _signals.signal("appcontext-tearing-down")
appcontext_pushed = _signals.signal("appcontext-pushed")
appcontext_popped = _signals.signal("appcontext-popped")
message_flashed = _signals.signal("message-flashed")


Filepath: githubCode\src\flask\templating.py:

from __future__ import annotations

import typing as t

from jinja2 import BaseLoader
from jinja2 import Environment as BaseEnvironment
from jinja2 import Template
from jinja2 import TemplateNotFound

from .globals import _cv_app
from .globals import _cv_request
from .globals import current_app
from .globals import request
from .helpers import stream_with_context
from .signals import before_render_template
from .signals import template_rendered

if t.TYPE_CHECKING:  # pragma: no cover
    from .app import Flask
    from .sansio.app import App
    from .sansio.scaffold import Scaffold


def _default_template_ctx_processor() -> dict[str, t.Any]:
    """Default template context processor.  Injects `request`,
    `session` and `g`.
    """
    appctx = _cv_app.get(None)
    reqctx = _cv_request.get(None)
    rv: dict[str, t.Any] = {}
    if appctx is not None:
        rv["g"] = appctx.g
    if reqctx is not None:
        rv["request"] = reqctx.request
        rv["session"] = reqctx.session
    return rv


class Environment(BaseEnvironment):
    """Works like a regular Jinja2 environment but has some additional
    knowledge of how Flask's blueprint works so that it can prepend the
    name of the blueprint to referenced templates if necessary.
    """

    def __init__(self, app: App, **options: t.Any) -> None:
        if "loader" not in options:
            options["loader"] = app.create_global_jinja_loader()
        BaseEnvironment.__init__(self, **options)
        self.app = app


class DispatchingJinjaLoader(BaseLoader):
    """A loader that looks for templates in the application and all
    the blueprint folders.
    """

    def __init__(self, app: App) -> None:
        self.app = app

    def get_source(
        self, environment: BaseEnvironment, template: str
    ) -> tuple[str, str | None, t.Callable[[], bool] | None]:
        if self.app.config["EXPLAIN_TEMPLATE_LOADING"]:
            return self._get_source_explained(environment, template)
        return self._get_source_fast(environment, template)

    def _get_source_explained(
        self, environment: BaseEnvironment, template: str
    ) -> tuple[str, str | None, t.Callable[[], bool] | None]:
        attempts = []
        rv: tuple[str, str | None, t.Callable[[], bool] | None] | None
        trv: None | (tuple[str, str | None, t.Callable[[], bool] | None]) = None

        for srcobj, loader in self._iter_loaders(template):
            try:
                rv = loader.get_source(environment, template)
                if trv is None:
                    trv = rv
            except TemplateNotFound:
                rv = None
            attempts.append((loader, srcobj, rv))

        from .debughelpers import explain_template_loading_attempts

        explain_template_loading_attempts(self.app, template, attempts)

        if trv is not None:
            return trv
        raise TemplateNotFound(template)

    def _get_source_fast(
        self, environment: BaseEnvironment, template: str
    ) -> tuple[str, str | None, t.Callable[[], bool] | None]:
        for _srcobj, loader in self._iter_loaders(template):
            try:
                return loader.get_source(environment, template)
            except TemplateNotFound:
                continue
        raise TemplateNotFound(template)

    def _iter_loaders(self, template: str) -> t.Iterator[tuple[Scaffold, BaseLoader]]:
        loader = self.app.jinja_loader
        if loader is not None:
            yield self.app, loader

        for blueprint in self.app.iter_blueprints():
            loader = blueprint.jinja_loader
            if loader is not None:
                yield blueprint, loader

    def list_templates(self) -> list[str]:
        result = set()
        loader = self.app.jinja_loader
        if loader is not None:
            result.update(loader.list_templates())

        for blueprint in self.app.iter_blueprints():
            loader = blueprint.jinja_loader
            if loader is not None:
                for template in loader.list_templates():
                    result.add(template)

        return list(result)


def _render(app: Flask, template: Template, context: dict[str, t.Any]) -> str:
    app.update_template_context(context)
    before_render_template.send(
        app, _async_wrapper=app.ensure_sync, template=template, context=context
    )
    rv = template.render(context)
    template_rendered.send(
        app, _async_wrapper=app.ensure_sync, template=template, context=context
    )
    return rv


def render_template(
    template_name_or_list: str | Template | list[str | Template],
    **context: t.Any,
) -> str:
    """Render a template by name with the given context.

    :param template_name_or_list: The name of the template to render. If
        a list is given, the first name to exist will be rendered.
    :param context: The variables to make available in the template.
    """
    app = current_app._get_current_object()  # type: ignore[attr-defined]
    template = app.jinja_env.get_or_select_template(template_name_or_list)
    return _render(app, template, context)


def render_template_string(source: str, **context: t.Any) -> str:
    """Render a template from the given source string with the given
    context.

    :param source: The source code of the template to render.
    :param context: The variables to make available in the template.
    """
    app = current_app._get_current_object()  # type: ignore[attr-defined]
    template = app.jinja_env.from_string(source)
    return _render(app, template, context)


def _stream(
    app: Flask, template: Template, context: dict[str, t.Any]
) -> t.Iterator[str]:
    app.update_template_context(context)
    before_render_template.send(
        app, _async_wrapper=app.ensure_sync, template=template, context=context
    )

    def generate() -> t.Iterator[str]:
        yield from template.generate(context)
        template_rendered.send(
            app, _async_wrapper=app.ensure_sync, template=template, context=context
        )

    rv = generate()

    # If a request context is active, keep it while generating.
    if request:
        rv = stream_with_context(rv)

    return rv


def stream_template(
    template_name_or_list: str | Template | list[str | Template],
    **context: t.Any,
) -> t.Iterator[str]:
    """Render a template by name with the given context as a stream.
    This returns an iterator of strings, which can be used as a
    streaming response from a view.

    :param template_name_or_list: The name of the template to render. If
        a list is given, the first name to exist will be rendered.
    :param context: The variables to make available in the template.

    .. versionadded:: 2.2
    """
    app = current_app._get_current_object()  # type: ignore[attr-defined]
    template = app.jinja_env.get_or_select_template(template_name_or_list)
    return _stream(app, template, context)


def stream_template_string(source: str, **context: t.Any) -> t.Iterator[str]:
    """Render a template from the given source string with the given
    context as a stream. This returns an iterator of strings, which can
    be used as a streaming response from a view.

    :param source: The source code of the template to render.
    :param context: The variables to make available in the template.

    .. versionadded:: 2.2
    """
    app = current_app._get_current_object()  # type: ignore[attr-defined]
    template = app.jinja_env.from_string(source)
    return _stream(app, template, context)


Filepath: githubCode\src\flask\testing.py:

from __future__ import annotations

import importlib.metadata
import typing as t
from contextlib import contextmanager
from contextlib import ExitStack
from copy import copy
from types import TracebackType
from urllib.parse import urlsplit

import werkzeug.test
from click.testing import CliRunner
from werkzeug.test import Client
from werkzeug.wrappers import Request as BaseRequest

from .cli import ScriptInfo
from .sessions import SessionMixin

if t.TYPE_CHECKING:  # pragma: no cover
    from _typeshed.wsgi import WSGIEnvironment
    from werkzeug.test import TestResponse

    from .app import Flask


class EnvironBuilder(werkzeug.test.EnvironBuilder):
    """An :class:`~werkzeug.test.EnvironBuilder`, that takes defaults from the
    application.

    :param app: The Flask application to configure the environment from.
    :param path: URL path being requested.
    :param base_url: Base URL where the app is being served, which
        ``path`` is relative to. If not given, built from
        :data:`PREFERRED_URL_SCHEME`, ``subdomain``,
        :data:`SERVER_NAME`, and :data:`APPLICATION_ROOT`.
    :param subdomain: Subdomain name to append to :data:`SERVER_NAME`.
    :param url_scheme: Scheme to use instead of
        :data:`PREFERRED_URL_SCHEME`.
    :param json: If given, this is serialized as JSON and passed as
        ``data``. Also defaults ``content_type`` to
        ``application/json``.
    :param args: other positional arguments passed to
        :class:`~werkzeug.test.EnvironBuilder`.
    :param kwargs: other keyword arguments passed to
        :class:`~werkzeug.test.EnvironBuilder`.
    """

    def __init__(
        self,
        app: Flask,
        path: str = "/",
        base_url: str | None = None,
        subdomain: str | None = None,
        url_scheme: str | None = None,
        *args: t.Any,
        **kwargs: t.Any,
    ) -> None:
        assert not (base_url or subdomain or url_scheme) or (
            base_url is not None
        ) != bool(
            subdomain or url_scheme
        ), 'Cannot pass "subdomain" or "url_scheme" with "base_url".'

        if base_url is None:
            http_host = app.config.get("SERVER_NAME") or "localhost"
            app_root = app.config["APPLICATION_ROOT"]

            if subdomain:
                http_host = f"{subdomain}.{http_host}"

            if url_scheme is None:
                url_scheme = app.config["PREFERRED_URL_SCHEME"]

            url = urlsplit(path)
            base_url = (
                f"{url.scheme or url_scheme}://{url.netloc or http_host}"
                f"/{app_root.lstrip('/')}"
            )
            path = url.path

            if url.query:
                sep = b"?" if isinstance(url.query, bytes) else "?"
                path += sep + url.query

        self.app = app
        super().__init__(path, base_url, *args, **kwargs)

    def json_dumps(self, obj: t.Any, **kwargs: t.Any) -> str:  # type: ignore
        """Serialize ``obj`` to a JSON-formatted string.

        The serialization will be configured according to the config associated
        with this EnvironBuilder's ``app``.
        """
        return self.app.json.dumps(obj, **kwargs)


_werkzeug_version = ""


def _get_werkzeug_version() -> str:
    global _werkzeug_version

    if not _werkzeug_version:
        _werkzeug_version = importlib.metadata.version("werkzeug")

    return _werkzeug_version


class FlaskClient(Client):
    """Works like a regular Werkzeug test client but has knowledge about
    Flask's contexts to defer the cleanup of the request context until
    the end of a ``with`` block. For general information about how to
    use this class refer to :class:`werkzeug.test.Client`.

    .. versionchanged:: 0.12
       `app.test_client()` includes preset default environment, which can be
       set after instantiation of the `app.test_client()` object in
       `client.environ_base`.

    Basic usage is outlined in the :doc:`/testing` chapter.
    """

    application: Flask

    def __init__(self, *args: t.Any, **kwargs: t.Any) -> None:
        super().__init__(*args, **kwargs)
        self.preserve_context = False
        self._new_contexts: list[t.ContextManager[t.Any]] = []
        self._context_stack = ExitStack()
        self.environ_base = {
            "REMOTE_ADDR": "127.0.0.1",
            "HTTP_USER_AGENT": f"Werkzeug/{_get_werkzeug_version()}",
        }

    @contextmanager
    def session_transaction(
        self, *args: t.Any, **kwargs: t.Any
    ) -> t.Iterator[SessionMixin]:
        """When used in combination with a ``with`` statement this opens a
        session transaction.  This can be used to modify the session that
        the test client uses.  Once the ``with`` block is left the session is
        stored back.

        ::

            with client.session_transaction() as session:
                session['value'] = 42

        Internally this is implemented by going through a temporary test
        request context and since session handling could depend on
        request variables this function accepts the same arguments as
        :meth:`~flask.Flask.test_request_context` which are directly
        passed through.
        """
        if self._cookies is None:
            raise TypeError(
                "Cookies are disabled. Create a client with 'use_cookies=True'."
            )

        app = self.application
        ctx = app.test_request_context(*args, **kwargs)
        self._add_cookies_to_wsgi(ctx.request.environ)

        with ctx:
            sess = app.session_interface.open_session(app, ctx.request)

        if sess is None:
            raise RuntimeError("Session backend did not open a session.")

        yield sess
        resp = app.response_class()

        if app.session_interface.is_null_session(sess):
            return

        with ctx:
            app.session_interface.save_session(app, sess, resp)

        self._update_cookies_from_response(
            ctx.request.host.partition(":")[0],
            ctx.request.path,
            resp.headers.getlist("Set-Cookie"),
        )

    def _copy_environ(self, other: WSGIEnvironment) -> WSGIEnvironment:
        out = {**self.environ_base, **other}

        if self.preserve_context:
            out["werkzeug.debug.preserve_context"] = self._new_contexts.append

        return out

    def _request_from_builder_args(
        self, args: tuple[t.Any, ...], kwargs: dict[str, t.Any]
    ) -> BaseRequest:
        kwargs["environ_base"] = self._copy_environ(kwargs.get("environ_base", {}))
        builder = EnvironBuilder(self.application, *args, **kwargs)

        try:
            return builder.get_request()
        finally:
            builder.close()

    def open(
        self,
        *args: t.Any,
        buffered: bool = False,
        follow_redirects: bool = False,
        **kwargs: t.Any,
    ) -> TestResponse:
        if args and isinstance(
            args[0], (werkzeug.test.EnvironBuilder, dict, BaseRequest)
        ):
            if isinstance(args[0], werkzeug.test.EnvironBuilder):
                builder = copy(args[0])
                builder.environ_base = self._copy_environ(builder.environ_base or {})  # type: ignore[arg-type]
                request = builder.get_request()
            elif isinstance(args[0], dict):
                request = EnvironBuilder.from_environ(
                    args[0], app=self.application, environ_base=self._copy_environ({})
                ).get_request()
            else:
                # isinstance(args[0], BaseRequest)
                request = copy(args[0])
                request.environ = self._copy_environ(request.environ)
        else:
            # request is None
            request = self._request_from_builder_args(args, kwargs)

        # Pop any previously preserved contexts. This prevents contexts
        # from being preserved across redirects or multiple requests
        # within a single block.
        self._context_stack.close()

        response = super().open(
            request,
            buffered=buffered,
            follow_redirects=follow_redirects,
        )
        response.json_module = self.application.json  # type: ignore[assignment]

        # Re-push contexts that were preserved during the request.
        while self._new_contexts:
            cm = self._new_contexts.pop()
            self._context_stack.enter_context(cm)

        return response

    def __enter__(self) -> FlaskClient:
        if self.preserve_context:
            raise RuntimeError("Cannot nest client invocations")
        self.preserve_context = True
        return self

    def __exit__(
        self,
        exc_type: type | None,
        exc_value: BaseException | None,
        tb: TracebackType | None,
    ) -> None:
        self.preserve_context = False
        self._context_stack.close()


class FlaskCliRunner(CliRunner):
    """A :class:`~click.testing.CliRunner` for testing a Flask app's
    CLI commands. Typically created using
    :meth:`~flask.Flask.test_cli_runner`. See :ref:`testing-cli`.
    """

    def __init__(self, app: Flask, **kwargs: t.Any) -> None:
        self.app = app
        super().__init__(**kwargs)

    def invoke(  # type: ignore
        self, cli: t.Any = None, args: t.Any = None, **kwargs: t.Any
    ) -> t.Any:
        """Invokes a CLI command in an isolated environment. See
        :meth:`CliRunner.invoke <click.testing.CliRunner.invoke>` for
        full method documentation. See :ref:`testing-cli` for examples.

        If the ``obj`` argument is not given, passes an instance of
        :class:`~flask.cli.ScriptInfo` that knows how to load the Flask
        app being tested.

        :param cli: Command object to invoke. Default is the app's
            :attr:`~flask.app.Flask.cli` group.
        :param args: List of strings to invoke the command with.

        :return: a :class:`~click.testing.Result` object.
        """
        if cli is None:
            cli = self.app.cli

        if "obj" not in kwargs:
            kwargs["obj"] = ScriptInfo(create_app=lambda: self.app)

        return super().invoke(cli, args, **kwargs)


Filepath: githubCode\src\flask\typing.py:

from __future__ import annotations

import typing as t

if t.TYPE_CHECKING:  # pragma: no cover
    from _typeshed.wsgi import WSGIApplication  # noqa: F401
    from werkzeug.datastructures import Headers  # noqa: F401
    from werkzeug.sansio.response import Response  # noqa: F401

# The possible types that are directly convertible or are a Response object.
ResponseValue = t.Union[
    "Response",
    str,
    bytes,
    t.List[t.Any],
    # Only dict is actually accepted, but Mapping allows for TypedDict.
    t.Mapping[str, t.Any],
    t.Iterator[str],
    t.Iterator[bytes],
]

# the possible types for an individual HTTP header
# This should be a Union, but mypy doesn't pass unless it's a TypeVar.
HeaderValue = t.Union[str, t.List[str], t.Tuple[str, ...]]

# the possible types for HTTP headers
HeadersValue = t.Union[
    "Headers",
    t.Mapping[str, HeaderValue],
    t.Sequence[t.Tuple[str, HeaderValue]],
]

# The possible types returned by a route function.
ResponseReturnValue = t.Union[
    ResponseValue,
    t.Tuple[ResponseValue, HeadersValue],
    t.Tuple[ResponseValue, int],
    t.Tuple[ResponseValue, int, HeadersValue],
    "WSGIApplication",
]

# Allow any subclass of werkzeug.Response, such as the one from Flask,
# as a callback argument. Using werkzeug.Response directly makes a
# callback annotated with flask.Response fail type checking.
ResponseClass = t.TypeVar("ResponseClass", bound="Response")

AppOrBlueprintKey = t.Optional[str]  # The App key is None, whereas blueprints are named
AfterRequestCallable = t.Union[
    t.Callable[[ResponseClass], ResponseClass],
    t.Callable[[ResponseClass], t.Awaitable[ResponseClass]],
]
BeforeFirstRequestCallable = t.Union[
    t.Callable[[], None], t.Callable[[], t.Awaitable[None]]
]
BeforeRequestCallable = t.Union[
    t.Callable[[], t.Optional[ResponseReturnValue]],
    t.Callable[[], t.Awaitable[t.Optional[ResponseReturnValue]]],
]
ShellContextProcessorCallable = t.Callable[[], t.Dict[str, t.Any]]
TeardownCallable = t.Union[
    t.Callable[[t.Optional[BaseException]], None],
    t.Callable[[t.Optional[BaseException]], t.Awaitable[None]],
]
TemplateContextProcessorCallable = t.Union[
    t.Callable[[], t.Dict[str, t.Any]],
    t.Callable[[], t.Awaitable[t.Dict[str, t.Any]]],
]
TemplateFilterCallable = t.Callable[..., t.Any]
TemplateGlobalCallable = t.Callable[..., t.Any]
TemplateTestCallable = t.Callable[..., bool]
URLDefaultCallable = t.Callable[[str, t.Dict[str, t.Any]], None]
URLValuePreprocessorCallable = t.Callable[
    [t.Optional[str], t.Optional[t.Dict[str, t.Any]]], None
]

# This should take Exception, but that either breaks typing the argument
# with a specific exception, or decorating multiple times with different
# exceptions (and using a union type on the argument).
# https://github.com/pallets/flask/issues/4095
# https://github.com/pallets/flask/issues/4295
# https://github.com/pallets/flask/issues/4297
ErrorHandlerCallable = t.Union[
    t.Callable[[t.Any], ResponseReturnValue],
    t.Callable[[t.Any], t.Awaitable[ResponseReturnValue]],
]

RouteCallable = t.Union[
    t.Callable[..., ResponseReturnValue],
    t.Callable[..., t.Awaitable[ResponseReturnValue]],
]


Filepath: githubCode\src\flask\views.py:

from __future__ import annotations

import typing as t

from . import typing as ft
from .globals import current_app
from .globals import request

F = t.TypeVar("F", bound=t.Callable[..., t.Any])

http_method_funcs = frozenset(
    ["get", "post", "head", "options", "delete", "put", "trace", "patch"]
)


class View:
    """Subclass this class and override :meth:`dispatch_request` to
    create a generic class-based view. Call :meth:`as_view` to create a
    view function that creates an instance of the class with the given
    arguments and calls its ``dispatch_request`` method with any URL
    variables.

    See :doc:`views` for a detailed guide.

    .. code-block:: python

        class Hello(View):
            init_every_request = False

            def dispatch_request(self, name):
                return f"Hello, {name}!"

        app.add_url_rule(
            "/hello/<name>", view_func=Hello.as_view("hello")
        )

    Set :attr:`methods` on the class to change what methods the view
    accepts.

    Set :attr:`decorators` on the class to apply a list of decorators to
    the generated view function. Decorators applied to the class itself
    will not be applied to the generated view function!

    Set :attr:`init_every_request` to ``False`` for efficiency, unless
    you need to store request-global data on ``self``.
    """

    #: The methods this view is registered for. Uses the same default
    #: (``["GET", "HEAD", "OPTIONS"]``) as ``route`` and
    #: ``add_url_rule`` by default.
    methods: t.ClassVar[t.Collection[str] | None] = None

    #: Control whether the ``OPTIONS`` method is handled automatically.
    #: Uses the same default (``True``) as ``route`` and
    #: ``add_url_rule`` by default.
    provide_automatic_options: t.ClassVar[bool | None] = None

    #: A list of decorators to apply, in order, to the generated view
    #: function. Remember that ``@decorator`` syntax is applied bottom
    #: to top, so the first decorator in the list would be the bottom
    #: decorator.
    #:
    #: .. versionadded:: 0.8
    decorators: t.ClassVar[list[t.Callable[[F], F]]] = []

    #: Create a new instance of this view class for every request by
    #: default. If a view subclass sets this to ``False``, the same
    #: instance is used for every request.
    #:
    #: A single instance is more efficient, especially if complex setup
    #: is done during init. However, storing data on ``self`` is no
    #: longer safe across requests, and :data:`~flask.g` should be used
    #: instead.
    #:
    #: .. versionadded:: 2.2
    init_every_request: t.ClassVar[bool] = True

    def dispatch_request(self) -> ft.ResponseReturnValue:
        """The actual view function behavior. Subclasses must override
        this and return a valid response. Any variables from the URL
        rule are passed as keyword arguments.
        """
        raise NotImplementedError()

    @classmethod
    def as_view(
        cls, name: str, *class_args: t.Any, **class_kwargs: t.Any
    ) -> ft.RouteCallable:
        """Convert the class into a view function that can be registered
        for a route.

        By default, the generated view will create a new instance of the
        view class for every request and call its
        :meth:`dispatch_request` method. If the view class sets
        :attr:`init_every_request` to ``False``, the same instance will
        be used for every request.

        Except for ``name``, all other arguments passed to this method
        are forwarded to the view class ``__init__`` method.

        .. versionchanged:: 2.2
            Added the ``init_every_request`` class attribute.
        """
        if cls.init_every_request:

            def view(**kwargs: t.Any) -> ft.ResponseReturnValue:
                self = view.view_class(  # type: ignore[attr-defined]
                    *class_args, **class_kwargs
                )
                return current_app.ensure_sync(self.dispatch_request)(**kwargs)  # type: ignore[no-any-return]

        else:
            self = cls(*class_args, **class_kwargs)

            def view(**kwargs: t.Any) -> ft.ResponseReturnValue:
                return current_app.ensure_sync(self.dispatch_request)(**kwargs)  # type: ignore[no-any-return]

        if cls.decorators:
            view.__name__ = name
            view.__module__ = cls.__module__
            for decorator in cls.decorators:
                view = decorator(view)

        # We attach the view class to the view function for two reasons:
        # first of all it allows us to easily figure out what class-based
        # view this thing came from, secondly it's also used for instantiating
        # the view class so you can actually replace it with something else
        # for testing purposes and debugging.
        view.view_class = cls  # type: ignore
        view.__name__ = name
        view.__doc__ = cls.__doc__
        view.__module__ = cls.__module__
        view.methods = cls.methods  # type: ignore
        view.provide_automatic_options = cls.provide_automatic_options  # type: ignore
        return view


class MethodView(View):
    """Dispatches request methods to the corresponding instance methods.
    For example, if you implement a ``get`` method, it will be used to
    handle ``GET`` requests.

    This can be useful for defining a REST API.

    :attr:`methods` is automatically set based on the methods defined on
    the class.

    See :doc:`views` for a detailed guide.

    .. code-block:: python

        class CounterAPI(MethodView):
            def get(self):
                return str(session.get("counter", 0))

            def post(self):
                session["counter"] = session.get("counter", 0) + 1
                return redirect(url_for("counter"))

        app.add_url_rule(
            "/counter", view_func=CounterAPI.as_view("counter")
        )
    """

    def __init_subclass__(cls, **kwargs: t.Any) -> None:
        super().__init_subclass__(**kwargs)

        if "methods" not in cls.__dict__:
            methods = set()

            for base in cls.__bases__:
                if getattr(base, "methods", None):
                    methods.update(base.methods)  # type: ignore[attr-defined]

            for key in http_method_funcs:
                if hasattr(cls, key):
                    methods.add(key.upper())

            if methods:
                cls.methods = methods

    def dispatch_request(self, **kwargs: t.Any) -> ft.ResponseReturnValue:
        meth = getattr(self, request.method.lower(), None)

        # If the request method is HEAD and we don't have a handler for it
        # retry with GET.
        if meth is None and request.method == "HEAD":
            meth = getattr(self, "get", None)

        assert meth is not None, f"Unimplemented method {request.method!r}"
        return current_app.ensure_sync(meth)(**kwargs)  # type: ignore[no-any-return]


Filepath: githubCode\src\flask\wrappers.py:

from __future__ import annotations

import typing as t

from werkzeug.exceptions import BadRequest
from werkzeug.exceptions import HTTPException
from werkzeug.wrappers import Request as RequestBase
from werkzeug.wrappers import Response as ResponseBase

from . import json
from .globals import current_app
from .helpers import _split_blueprint_path

if t.TYPE_CHECKING:  # pragma: no cover
    from werkzeug.routing import Rule


class Request(RequestBase):
    """The request object used by default in Flask.  Remembers the
    matched endpoint and view arguments.

    It is what ends up as :class:`~flask.request`.  If you want to replace
    the request object used you can subclass this and set
    :attr:`~flask.Flask.request_class` to your subclass.

    The request object is a :class:`~werkzeug.wrappers.Request` subclass and
    provides all of the attributes Werkzeug defines plus a few Flask
    specific ones.
    """

    json_module: t.Any = json

    #: The internal URL rule that matched the request.  This can be
    #: useful to inspect which methods are allowed for the URL from
    #: a before/after handler (``request.url_rule.methods``) etc.
    #: Though if the request's method was invalid for the URL rule,
    #: the valid list is available in ``routing_exception.valid_methods``
    #: instead (an attribute of the Werkzeug exception
    #: :exc:`~werkzeug.exceptions.MethodNotAllowed`)
    #: because the request was never internally bound.
    #:
    #: .. versionadded:: 0.6
    url_rule: Rule | None = None

    #: A dict of view arguments that matched the request.  If an exception
    #: happened when matching, this will be ``None``.
    view_args: dict[str, t.Any] | None = None

    #: If matching the URL failed, this is the exception that will be
    #: raised / was raised as part of the request handling.  This is
    #: usually a :exc:`~werkzeug.exceptions.NotFound` exception or
    #: something similar.
    routing_exception: HTTPException | None = None

    @property
    def max_content_length(self) -> int | None:  # type: ignore[override]
        """Read-only view of the ``MAX_CONTENT_LENGTH`` config key."""
        if current_app:
            return current_app.config["MAX_CONTENT_LENGTH"]  # type: ignore[no-any-return]
        else:
            return None

    @property
    def endpoint(self) -> str | None:
        """The endpoint that matched the request URL.

        This will be ``None`` if matching failed or has not been
        performed yet.

        This in combination with :attr:`view_args` can be used to
        reconstruct the same URL or a modified URL.
        """
        if self.url_rule is not None:
            return self.url_rule.endpoint

        return None

    @property
    def blueprint(self) -> str | None:
        """The registered name of the current blueprint.

        This will be ``None`` if the endpoint is not part of a
        blueprint, or if URL matching failed or has not been performed
        yet.

        This does not necessarily match the name the blueprint was
        created with. It may have been nested, or registered with a
        different name.
        """
        endpoint = self.endpoint

        if endpoint is not None and "." in endpoint:
            return endpoint.rpartition(".")[0]

        return None

    @property
    def blueprints(self) -> list[str]:
        """The registered names of the current blueprint upwards through
        parent blueprints.

        This will be an empty list if there is no current blueprint, or
        if URL matching failed.

        .. versionadded:: 2.0.1
        """
        name = self.blueprint

        if name is None:
            return []

        return _split_blueprint_path(name)

    def _load_form_data(self) -> None:
        super()._load_form_data()

        # In debug mode we're replacing the files multidict with an ad-hoc
        # subclass that raises a different error for key errors.
        if (
            current_app
            and current_app.debug
            and self.mimetype != "multipart/form-data"
            and not self.files
        ):
            from .debughelpers import attach_enctype_error_multidict

            attach_enctype_error_multidict(self)

    def on_json_loading_failed(self, e: ValueError | None) -> t.Any:
        try:
            return super().on_json_loading_failed(e)
        except BadRequest as e:
            if current_app and current_app.debug:
                raise

            raise BadRequest() from e


class Response(ResponseBase):
    """The response object that is used by default in Flask.  Works like the
    response object from Werkzeug but is set to have an HTML mimetype by
    default.  Quite often you don't have to create this object yourself because
    :meth:`~flask.Flask.make_response` will take care of that for you.

    If you want to replace the response object used you can subclass this and
    set :attr:`~flask.Flask.response_class` to your subclass.

    .. versionchanged:: 1.0
        JSON support is added to the response, like the request. This is useful
        when testing to get the test client response data as JSON.

    .. versionchanged:: 1.0

        Added :attr:`max_cookie_size`.
    """

    default_mimetype: str | None = "text/html"

    json_module = json

    autocorrect_location_header = False

    @property
    def max_cookie_size(self) -> int:  # type: ignore
        """Read-only view of the :data:`MAX_COOKIE_SIZE` config key.

        See :attr:`~werkzeug.wrappers.Response.max_cookie_size` in
        Werkzeug's docs.
        """
        if current_app:
            return current_app.config["MAX_COOKIE_SIZE"]  # type: ignore[no-any-return]

        # return Werkzeug's default when not in an app context
        return super().max_cookie_size


Filepath: githubCode\src\flask\__init__.py:

from __future__ import annotations

import typing as t

from . import json as json
from .app import Flask as Flask
from .blueprints import Blueprint as Blueprint
from .config import Config as Config
from .ctx import after_this_request as after_this_request
from .ctx import copy_current_request_context as copy_current_request_context
from .ctx import has_app_context as has_app_context
from .ctx import has_request_context as has_request_context
from .globals import current_app as current_app
from .globals import g as g
from .globals import request as request
from .globals import session as session
from .helpers import abort as abort
from .helpers import flash as flash
from .helpers import get_flashed_messages as get_flashed_messages
from .helpers import get_template_attribute as get_template_attribute
from .helpers import make_response as make_response
from .helpers import redirect as redirect
from .helpers import send_file as send_file
from .helpers import send_from_directory as send_from_directory
from .helpers import stream_with_context as stream_with_context
from .helpers import url_for as url_for
from .json import jsonify as jsonify
from .signals import appcontext_popped as appcontext_popped
from .signals import appcontext_pushed as appcontext_pushed
from .signals import appcontext_tearing_down as appcontext_tearing_down
from .signals import before_render_template as before_render_template
from .signals import got_request_exception as got_request_exception
from .signals import message_flashed as message_flashed
from .signals import request_finished as request_finished
from .signals import request_started as request_started
from .signals import request_tearing_down as request_tearing_down
from .signals import template_rendered as template_rendered
from .templating import render_template as render_template
from .templating import render_template_string as render_template_string
from .templating import stream_template as stream_template
from .templating import stream_template_string as stream_template_string
from .wrappers import Request as Request
from .wrappers import Response as Response


def __getattr__(name: str) -> t.Any:
    if name == "__version__":
        import importlib.metadata
        import warnings

        warnings.warn(
            "The '__version__' attribute is deprecated and will be removed in"
            " Flask 3.1. Use feature detection or"
            " 'importlib.metadata.version(\"flask\")' instead.",
            DeprecationWarning,
            stacklevel=2,
        )
        return importlib.metadata.version("flask")

    raise AttributeError(name)


Filepath: githubCode\src\flask\__main__.py:

from .cli import main

main()


Filepath: githubCode\src\flask\json\provider.py:

from __future__ import annotations

import dataclasses
import decimal
import json
import typing as t
import uuid
import weakref
from datetime import date

from werkzeug.http import http_date

if t.TYPE_CHECKING:  # pragma: no cover
    from werkzeug.sansio.response import Response

    from ..sansio.app import App


class JSONProvider:
    """A standard set of JSON operations for an application. Subclasses
    of this can be used to customize JSON behavior or use different
    JSON libraries.

    To implement a provider for a specific library, subclass this base
    class and implement at least :meth:`dumps` and :meth:`loads`. All
    other methods have default implementations.

    To use a different provider, either subclass ``Flask`` and set
    :attr:`~flask.Flask.json_provider_class` to a provider class, or set
    :attr:`app.json <flask.Flask.json>` to an instance of the class.

    :param app: An application instance. This will be stored as a
        :class:`weakref.proxy` on the :attr:`_app` attribute.

    .. versionadded:: 2.2
    """

    def __init__(self, app: App) -> None:
        self._app: App = weakref.proxy(app)

    def dumps(self, obj: t.Any, **kwargs: t.Any) -> str:
        """Serialize data as JSON.

        :param obj: The data to serialize.
        :param kwargs: May be passed to the underlying JSON library.
        """
        raise NotImplementedError

    def dump(self, obj: t.Any, fp: t.IO[str], **kwargs: t.Any) -> None:
        """Serialize data as JSON and write to a file.

        :param obj: The data to serialize.
        :param fp: A file opened for writing text. Should use the UTF-8
            encoding to be valid JSON.
        :param kwargs: May be passed to the underlying JSON library.
        """
        fp.write(self.dumps(obj, **kwargs))

    def loads(self, s: str | bytes, **kwargs: t.Any) -> t.Any:
        """Deserialize data as JSON.

        :param s: Text or UTF-8 bytes.
        :param kwargs: May be passed to the underlying JSON library.
        """
        raise NotImplementedError

    def load(self, fp: t.IO[t.AnyStr], **kwargs: t.Any) -> t.Any:
        """Deserialize data as JSON read from a file.

        :param fp: A file opened for reading text or UTF-8 bytes.
        :param kwargs: May be passed to the underlying JSON library.
        """
        return self.loads(fp.read(), **kwargs)

    def _prepare_response_obj(
        self, args: tuple[t.Any, ...], kwargs: dict[str, t.Any]
    ) -> t.Any:
        if args and kwargs:
            raise TypeError("app.json.response() takes either args or kwargs, not both")

        if not args and not kwargs:
            return None

        if len(args) == 1:
            return args[0]

        return args or kwargs

    def response(self, *args: t.Any, **kwargs: t.Any) -> Response:
        """Serialize the given arguments as JSON, and return a
        :class:`~flask.Response` object with the ``application/json``
        mimetype.

        The :func:`~flask.json.jsonify` function calls this method for
        the current application.

        Either positional or keyword arguments can be given, not both.
        If no arguments are given, ``None`` is serialized.

        :param args: A single value to serialize, or multiple values to
            treat as a list to serialize.
        :param kwargs: Treat as a dict to serialize.
        """
        obj = self._prepare_response_obj(args, kwargs)
        return self._app.response_class(self.dumps(obj), mimetype="application/json")


def _default(o: t.Any) -> t.Any:
    if isinstance(o, date):
        return http_date(o)

    if isinstance(o, (decimal.Decimal, uuid.UUID)):
        return str(o)

    if dataclasses and dataclasses.is_dataclass(o):
        return dataclasses.asdict(o)

    if hasattr(o, "__html__"):
        return str(o.__html__())

    raise TypeError(f"Object of type {type(o).__name__} is not JSON serializable")


class DefaultJSONProvider(JSONProvider):
    """Provide JSON operations using Python's built-in :mod:`json`
    library. Serializes the following additional data types:

    -   :class:`datetime.datetime` and :class:`datetime.date` are
        serialized to :rfc:`822` strings. This is the same as the HTTP
        date format.
    -   :class:`uuid.UUID` is serialized to a string.
    -   :class:`dataclasses.dataclass` is passed to
        :func:`dataclasses.asdict`.
    -   :class:`~markupsafe.Markup` (or any object with a ``__html__``
        method) will call the ``__html__`` method to get a string.
    """

    default: t.Callable[[t.Any], t.Any] = staticmethod(_default)  # type: ignore[assignment]
    """Apply this function to any object that :meth:`json.dumps` does
    not know how to serialize. It should return a valid JSON type or
    raise a ``TypeError``.
    """

    ensure_ascii = True
    """Replace non-ASCII characters with escape sequences. This may be
    more compatible with some clients, but can be disabled for better
    performance and size.
    """

    sort_keys = True
    """Sort the keys in any serialized dicts. This may be useful for
    some caching situations, but can be disabled for better performance.
    When enabled, keys must all be strings, they are not converted
    before sorting.
    """

    compact: bool | None = None
    """If ``True``, or ``None`` out of debug mode, the :meth:`response`
    output will not add indentation, newlines, or spaces. If ``False``,
    or ``None`` in debug mode, it will use a non-compact representation.
    """

    mimetype = "application/json"
    """The mimetype set in :meth:`response`."""

    def dumps(self, obj: t.Any, **kwargs: t.Any) -> str:
        """Serialize data as JSON to a string.

        Keyword arguments are passed to :func:`json.dumps`. Sets some
        parameter defaults from the :attr:`default`,
        :attr:`ensure_ascii`, and :attr:`sort_keys` attributes.

        :param obj: The data to serialize.
        :param kwargs: Passed to :func:`json.dumps`.
        """
        kwargs.setdefault("default", self.default)
        kwargs.setdefault("ensure_ascii", self.ensure_ascii)
        kwargs.setdefault("sort_keys", self.sort_keys)
        return json.dumps(obj, **kwargs)

    def loads(self, s: str | bytes, **kwargs: t.Any) -> t.Any:
        """Deserialize data as JSON from a string or bytes.

        :param s: Text or UTF-8 bytes.
        :param kwargs: Passed to :func:`json.loads`.
        """
        return json.loads(s, **kwargs)

    def response(self, *args: t.Any, **kwargs: t.Any) -> Response:
        """Serialize the given arguments as JSON, and return a
        :class:`~flask.Response` object with it. The response mimetype
        will be "application/json" and can be changed with
        :attr:`mimetype`.

        If :attr:`compact` is ``False`` or debug mode is enabled, the
        output will be formatted to be easier to read.

        Either positional or keyword arguments can be given, not both.
        If no arguments are given, ``None`` is serialized.

        :param args: A single value to serialize, or multiple values to
            treat as a list to serialize.
        :param kwargs: Treat as a dict to serialize.
        """
        obj = self._prepare_response_obj(args, kwargs)
        dump_args: dict[str, t.Any] = {}

        if (self.compact is None and self._app.debug) or self.compact is False:
            dump_args.setdefault("indent", 2)
        else:
            dump_args.setdefault("separators", (",", ":"))

        return self._app.response_class(
            f"{self.dumps(obj, **dump_args)}\n", mimetype=self.mimetype
        )


Filepath: githubCode\src\flask\json\tag.py:

"""
Tagged JSON
~~~~~~~~~~~

A compact representation for lossless serialization of non-standard JSON
types. :class:`~flask.sessions.SecureCookieSessionInterface` uses this
to serialize the session data, but it may be useful in other places. It
can be extended to support other types.

.. autoclass:: TaggedJSONSerializer
    :members:

.. autoclass:: JSONTag
    :members:

Let's see an example that adds support for
:class:`~collections.OrderedDict`. Dicts don't have an order in JSON, so
to handle this we will dump the items as a list of ``[key, value]``
pairs. Subclass :class:`JSONTag` and give it the new key ``' od'`` to
identify the type. The session serializer processes dicts first, so
insert the new tag at the front of the order since ``OrderedDict`` must
be processed before ``dict``.

.. code-block:: python

    from flask.json.tag import JSONTag

    class TagOrderedDict(JSONTag):
        __slots__ = ('serializer',)
        key = ' od'

        def check(self, value):
            return isinstance(value, OrderedDict)

        def to_json(self, value):
            return [[k, self.serializer.tag(v)] for k, v in iteritems(value)]

        def to_python(self, value):
            return OrderedDict(value)

    app.session_interface.serializer.register(TagOrderedDict, index=0)
"""
from __future__ import annotations

import typing as t
from base64 import b64decode
from base64 import b64encode
from datetime import datetime
from uuid import UUID

from markupsafe import Markup
from werkzeug.http import http_date
from werkzeug.http import parse_date

from ..json import dumps
from ..json import loads


class JSONTag:
    """Base class for defining type tags for :class:`TaggedJSONSerializer`."""

    __slots__ = ("serializer",)

    #: The tag to mark the serialized object with. If empty, this tag is
    #: only used as an intermediate step during tagging.
    key: str = ""

    def __init__(self, serializer: TaggedJSONSerializer) -> None:
        """Create a tagger for the given serializer."""
        self.serializer = serializer

    def check(self, value: t.Any) -> bool:
        """Check if the given value should be tagged by this tag."""
        raise NotImplementedError

    def to_json(self, value: t.Any) -> t.Any:
        """Convert the Python object to an object that is a valid JSON type.
        The tag will be added later."""
        raise NotImplementedError

    def to_python(self, value: t.Any) -> t.Any:
        """Convert the JSON representation back to the correct type. The tag
        will already be removed."""
        raise NotImplementedError

    def tag(self, value: t.Any) -> dict[str, t.Any]:
        """Convert the value to a valid JSON type and add the tag structure
        around it."""
        return {self.key: self.to_json(value)}


class TagDict(JSONTag):
    """Tag for 1-item dicts whose only key matches a registered tag.

    Internally, the dict key is suffixed with `__`, and the suffix is removed
    when deserializing.
    """

    __slots__ = ()
    key = " di"

    def check(self, value: t.Any) -> bool:
        return (
            isinstance(value, dict)
            and len(value) == 1
            and next(iter(value)) in self.serializer.tags
        )

    def to_json(self, value: t.Any) -> t.Any:
        key = next(iter(value))
        return {f"{key}__": self.serializer.tag(value[key])}

    def to_python(self, value: t.Any) -> t.Any:
        key = next(iter(value))
        return {key[:-2]: value[key]}


class PassDict(JSONTag):
    __slots__ = ()

    def check(self, value: t.Any) -> bool:
        return isinstance(value, dict)

    def to_json(self, value: t.Any) -> t.Any:
        # JSON objects may only have string keys, so don't bother tagging the
        # key here.
        return {k: self.serializer.tag(v) for k, v in value.items()}

    tag = to_json


class TagTuple(JSONTag):
    __slots__ = ()
    key = " t"

    def check(self, value: t.Any) -> bool:
        return isinstance(value, tuple)

    def to_json(self, value: t.Any) -> t.Any:
        return [self.serializer.tag(item) for item in value]

    def to_python(self, value: t.Any) -> t.Any:
        return tuple(value)


class PassList(JSONTag):
    __slots__ = ()

    def check(self, value: t.Any) -> bool:
        return isinstance(value, list)

    def to_json(self, value: t.Any) -> t.Any:
        return [self.serializer.tag(item) for item in value]

    tag = to_json


class TagBytes(JSONTag):
    __slots__ = ()
    key = " b"

    def check(self, value: t.Any) -> bool:
        return isinstance(value, bytes)

    def to_json(self, value: t.Any) -> t.Any:
        return b64encode(value).decode("ascii")

    def to_python(self, value: t.Any) -> t.Any:
        return b64decode(value)


class TagMarkup(JSONTag):
    """Serialize anything matching the :class:`~markupsafe.Markup` API by
    having a ``__html__`` method to the result of that method. Always
    deserializes to an instance of :class:`~markupsafe.Markup`."""

    __slots__ = ()
    key = " m"

    def check(self, value: t.Any) -> bool:
        return callable(getattr(value, "__html__", None))

    def to_json(self, value: t.Any) -> t.Any:
        return str(value.__html__())

    def to_python(self, value: t.Any) -> t.Any:
        return Markup(value)


class TagUUID(JSONTag):
    __slots__ = ()
    key = " u"

    def check(self, value: t.Any) -> bool:
        return isinstance(value, UUID)

    def to_json(self, value: t.Any) -> t.Any:
        return value.hex

    def to_python(self, value: t.Any) -> t.Any:
        return UUID(value)


class TagDateTime(JSONTag):
    __slots__ = ()
    key = " d"

    def check(self, value: t.Any) -> bool:
        return isinstance(value, datetime)

    def to_json(self, value: t.Any) -> t.Any:
        return http_date(value)

    def to_python(self, value: t.Any) -> t.Any:
        return parse_date(value)


class TaggedJSONSerializer:
    """Serializer that uses a tag system to compactly represent objects that
    are not JSON types. Passed as the intermediate serializer to
    :class:`itsdangerous.Serializer`.

    The following extra types are supported:

    * :class:`dict`
    * :class:`tuple`
    * :class:`bytes`
    * :class:`~markupsafe.Markup`
    * :class:`~uuid.UUID`
    * :class:`~datetime.datetime`
    """

    __slots__ = ("tags", "order")

    #: Tag classes to bind when creating the serializer. Other tags can be
    #: added later using :meth:`~register`.
    default_tags = [
        TagDict,
        PassDict,
        TagTuple,
        PassList,
        TagBytes,
        TagMarkup,
        TagUUID,
        TagDateTime,
    ]

    def __init__(self) -> None:
        self.tags: dict[str, JSONTag] = {}
        self.order: list[JSONTag] = []

        for cls in self.default_tags:
            self.register(cls)

    def register(
        self,
        tag_class: type[JSONTag],
        force: bool = False,
        index: int | None = None,
    ) -> None:
        """Register a new tag with this serializer.

        :param tag_class: tag class to register. Will be instantiated with this
            serializer instance.
        :param force: overwrite an existing tag. If false (default), a
            :exc:`KeyError` is raised.
        :param index: index to insert the new tag in the tag order. Useful when
            the new tag is a special case of an existing tag. If ``None``
            (default), the tag is appended to the end of the order.

        :raise KeyError: if the tag key is already registered and ``force`` is
            not true.
        """
        tag = tag_class(self)
        key = tag.key

        if key:
            if not force and key in self.tags:
                raise KeyError(f"Tag '{key}' is already registered.")

            self.tags[key] = tag

        if index is None:
            self.order.append(tag)
        else:
            self.order.insert(index, tag)

    def tag(self, value: t.Any) -> t.Any:
        """Convert a value to a tagged representation if necessary."""
        for tag in self.order:
            if tag.check(value):
                return tag.tag(value)

        return value

    def untag(self, value: dict[str, t.Any]) -> t.Any:
        """Convert a tagged representation back to the original type."""
        if len(value) != 1:
            return value

        key = next(iter(value))

        if key not in self.tags:
            return value

        return self.tags[key].to_python(value[key])

    def _untag_scan(self, value: t.Any) -> t.Any:
        if isinstance(value, dict):
            # untag each item recursively
            value = {k: self._untag_scan(v) for k, v in value.items()}
            # untag the dict itself
            value = self.untag(value)
        elif isinstance(value, list):
            # untag each item recursively
            value = [self._untag_scan(item) for item in value]

        return value

    def dumps(self, value: t.Any) -> str:
        """Tag the value and dump it to a compact JSON string."""
        return dumps(self.tag(value), separators=(",", ":"))

    def loads(self, value: str) -> t.Any:
        """Load data from a JSON string and deserialized any tagged objects."""
        return self._untag_scan(loads(value))


Filepath: githubCode\src\flask\json\__init__.py:

from __future__ import annotations

import json as _json
import typing as t

from ..globals import current_app
from .provider import _default

if t.TYPE_CHECKING:  # pragma: no cover
    from ..wrappers import Response


def dumps(obj: t.Any, **kwargs: t.Any) -> str:
    """Serialize data as JSON.

    If :data:`~flask.current_app` is available, it will use its
    :meth:`app.json.dumps() <flask.json.provider.JSONProvider.dumps>`
    method, otherwise it will use :func:`json.dumps`.

    :param obj: The data to serialize.
    :param kwargs: Arguments passed to the ``dumps`` implementation.

    .. versionchanged:: 2.3
        The ``app`` parameter was removed.

    .. versionchanged:: 2.2
        Calls ``current_app.json.dumps``, allowing an app to override
        the behavior.

    .. versionchanged:: 2.0.2
        :class:`decimal.Decimal` is supported by converting to a string.

    .. versionchanged:: 2.0
        ``encoding`` will be removed in Flask 2.1.

    .. versionchanged:: 1.0.3
        ``app`` can be passed directly, rather than requiring an app
        context for configuration.
    """
    if current_app:
        return current_app.json.dumps(obj, **kwargs)

    kwargs.setdefault("default", _default)
    return _json.dumps(obj, **kwargs)


def dump(obj: t.Any, fp: t.IO[str], **kwargs: t.Any) -> None:
    """Serialize data as JSON and write to a file.

    If :data:`~flask.current_app` is available, it will use its
    :meth:`app.json.dump() <flask.json.provider.JSONProvider.dump>`
    method, otherwise it will use :func:`json.dump`.

    :param obj: The data to serialize.
    :param fp: A file opened for writing text. Should use the UTF-8
        encoding to be valid JSON.
    :param kwargs: Arguments passed to the ``dump`` implementation.

    .. versionchanged:: 2.3
        The ``app`` parameter was removed.

    .. versionchanged:: 2.2
        Calls ``current_app.json.dump``, allowing an app to override
        the behavior.

    .. versionchanged:: 2.0
        Writing to a binary file, and the ``encoding`` argument, will be
        removed in Flask 2.1.
    """
    if current_app:
        current_app.json.dump(obj, fp, **kwargs)
    else:
        kwargs.setdefault("default", _default)
        _json.dump(obj, fp, **kwargs)


def loads(s: str | bytes, **kwargs: t.Any) -> t.Any:
    """Deserialize data as JSON.

    If :data:`~flask.current_app` is available, it will use its
    :meth:`app.json.loads() <flask.json.provider.JSONProvider.loads>`
    method, otherwise it will use :func:`json.loads`.

    :param s: Text or UTF-8 bytes.
    :param kwargs: Arguments passed to the ``loads`` implementation.

    .. versionchanged:: 2.3
        The ``app`` parameter was removed.

    .. versionchanged:: 2.2
        Calls ``current_app.json.loads``, allowing an app to override
        the behavior.

    .. versionchanged:: 2.0
        ``encoding`` will be removed in Flask 2.1. The data must be a
        string or UTF-8 bytes.

    .. versionchanged:: 1.0.3
        ``app`` can be passed directly, rather than requiring an app
        context for configuration.
    """
    if current_app:
        return current_app.json.loads(s, **kwargs)

    return _json.loads(s, **kwargs)


def load(fp: t.IO[t.AnyStr], **kwargs: t.Any) -> t.Any:
    """Deserialize data as JSON read from a file.

    If :data:`~flask.current_app` is available, it will use its
    :meth:`app.json.load() <flask.json.provider.JSONProvider.load>`
    method, otherwise it will use :func:`json.load`.

    :param fp: A file opened for reading text or UTF-8 bytes.
    :param kwargs: Arguments passed to the ``load`` implementation.

    .. versionchanged:: 2.3
        The ``app`` parameter was removed.

    .. versionchanged:: 2.2
        Calls ``current_app.json.load``, allowing an app to override
        the behavior.

    .. versionchanged:: 2.2
        The ``app`` parameter will be removed in Flask 2.3.

    .. versionchanged:: 2.0
        ``encoding`` will be removed in Flask 2.1. The file must be text
        mode, or binary mode with UTF-8 bytes.
    """
    if current_app:
        return current_app.json.load(fp, **kwargs)

    return _json.load(fp, **kwargs)


def jsonify(*args: t.Any, **kwargs: t.Any) -> Response:
    """Serialize the given arguments as JSON, and return a
    :class:`~flask.Response` object with the ``application/json``
    mimetype. A dict or list returned from a view will be converted to a
    JSON response automatically without needing to call this.

    This requires an active request or application context, and calls
    :meth:`app.json.response() <flask.json.provider.JSONProvider.response>`.

    In debug mode, the output is formatted with indentation to make it
    easier to read. This may also be controlled by the provider.

    Either positional or keyword arguments can be given, not both.
    If no arguments are given, ``None`` is serialized.

    :param args: A single value to serialize, or multiple values to
        treat as a list to serialize.
    :param kwargs: Treat as a dict to serialize.

    .. versionchanged:: 2.2
        Calls ``current_app.json.response``, allowing an app to override
        the behavior.

    .. versionchanged:: 2.0.2
        :class:`decimal.Decimal` is supported by converting to a string.

    .. versionchanged:: 0.11
        Added support for serializing top-level arrays. This was a
        security risk in ancient browsers. See :ref:`security-json`.

    .. versionadded:: 0.2
    """
    return current_app.json.response(*args, **kwargs)  # type: ignore[return-value]


Filepath: githubCode\src\flask\sansio\app.py:

from __future__ import annotations

import logging
import os
import sys
import typing as t
from datetime import timedelta
from itertools import chain

from werkzeug.exceptions import Aborter
from werkzeug.exceptions import BadRequest
from werkzeug.exceptions import BadRequestKeyError
from werkzeug.routing import BuildError
from werkzeug.routing import Map
from werkzeug.routing import Rule
from werkzeug.sansio.response import Response
from werkzeug.utils import cached_property
from werkzeug.utils import redirect as _wz_redirect

from .. import typing as ft
from ..config import Config
from ..config import ConfigAttribute
from ..ctx import _AppCtxGlobals
from ..helpers import _split_blueprint_path
from ..helpers import get_debug_flag
from ..json.provider import DefaultJSONProvider
from ..json.provider import JSONProvider
from ..logging import create_logger
from ..templating import DispatchingJinjaLoader
from ..templating import Environment
from .scaffold import _endpoint_from_view_func
from .scaffold import find_package
from .scaffold import Scaffold
from .scaffold import setupmethod

if t.TYPE_CHECKING:  # pragma: no cover
    from werkzeug.wrappers import Response as BaseResponse

    from ..testing import FlaskClient
    from ..testing import FlaskCliRunner
    from .blueprints import Blueprint

T_shell_context_processor = t.TypeVar(
    "T_shell_context_processor", bound=ft.ShellContextProcessorCallable
)
T_teardown = t.TypeVar("T_teardown", bound=ft.TeardownCallable)
T_template_filter = t.TypeVar("T_template_filter", bound=ft.TemplateFilterCallable)
T_template_global = t.TypeVar("T_template_global", bound=ft.TemplateGlobalCallable)
T_template_test = t.TypeVar("T_template_test", bound=ft.TemplateTestCallable)


def _make_timedelta(value: timedelta | int | None) -> timedelta | None:
    if value is None or isinstance(value, timedelta):
        return value

    return timedelta(seconds=value)


class App(Scaffold):
    """The flask object implements a WSGI application and acts as the central
    object.  It is passed the name of the module or package of the
    application.  Once it is created it will act as a central registry for
    the view functions, the URL rules, template configuration and much more.

    The name of the package is used to resolve resources from inside the
    package or the folder the module is contained in depending on if the
    package parameter resolves to an actual python package (a folder with
    an :file:`__init__.py` file inside) or a standard module (just a ``.py`` file).

    For more information about resource loading, see :func:`open_resource`.

    Usually you create a :class:`Flask` instance in your main module or
    in the :file:`__init__.py` file of your package like this::

        from flask import Flask
        app = Flask(__name__)

    .. admonition:: About the First Parameter

        The idea of the first parameter is to give Flask an idea of what
        belongs to your application.  This name is used to find resources
        on the filesystem, can be used by extensions to improve debugging
        information and a lot more.

        So it's important what you provide there.  If you are using a single
        module, `__name__` is always the correct value.  If you however are
        using a package, it's usually recommended to hardcode the name of
        your package there.

        For example if your application is defined in :file:`yourapplication/app.py`
        you should create it with one of the two versions below::

            app = Flask('yourapplication')
            app = Flask(__name__.split('.')[0])

        Why is that?  The application will work even with `__name__`, thanks
        to how resources are looked up.  However it will make debugging more
        painful.  Certain extensions can make assumptions based on the
        import name of your application.  For example the Flask-SQLAlchemy
        extension will look for the code in your application that triggered
        an SQL query in debug mode.  If the import name is not properly set
        up, that debugging information is lost.  (For example it would only
        pick up SQL queries in `yourapplication.app` and not
        `yourapplication.views.frontend`)

    .. versionadded:: 0.7
       The `static_url_path`, `static_folder`, and `template_folder`
       parameters were added.

    .. versionadded:: 0.8
       The `instance_path` and `instance_relative_config` parameters were
       added.

    .. versionadded:: 0.11
       The `root_path` parameter was added.

    .. versionadded:: 1.0
       The ``host_matching`` and ``static_host`` parameters were added.

    .. versionadded:: 1.0
       The ``subdomain_matching`` parameter was added. Subdomain
       matching needs to be enabled manually now. Setting
       :data:`SERVER_NAME` does not implicitly enable it.

    :param import_name: the name of the application package
    :param static_url_path: can be used to specify a different path for the
                            static files on the web.  Defaults to the name
                            of the `static_folder` folder.
    :param static_folder: The folder with static files that is served at
        ``static_url_path``. Relative to the application ``root_path``
        or an absolute path. Defaults to ``'static'``.
    :param static_host: the host to use when adding the static route.
        Defaults to None. Required when using ``host_matching=True``
        with a ``static_folder`` configured.
    :param host_matching: set ``url_map.host_matching`` attribute.
        Defaults to False.
    :param subdomain_matching: consider the subdomain relative to
        :data:`SERVER_NAME` when matching routes. Defaults to False.
    :param template_folder: the folder that contains the templates that should
                            be used by the application.  Defaults to
                            ``'templates'`` folder in the root path of the
                            application.
    :param instance_path: An alternative instance path for the application.
                          By default the folder ``'instance'`` next to the
                          package or module is assumed to be the instance
                          path.
    :param instance_relative_config: if set to ``True`` relative filenames
                                     for loading the config are assumed to
                                     be relative to the instance path instead
                                     of the application root.
    :param root_path: The path to the root of the application files.
        This should only be set manually when it can't be detected
        automatically, such as for namespace packages.
    """

    #: The class of the object assigned to :attr:`aborter`, created by
    #: :meth:`create_aborter`. That object is called by
    #: :func:`flask.abort` to raise HTTP errors, and can be
    #: called directly as well.
    #:
    #: Defaults to :class:`werkzeug.exceptions.Aborter`.
    #:
    #: .. versionadded:: 2.2
    aborter_class = Aborter

    #: The class that is used for the Jinja environment.
    #:
    #: .. versionadded:: 0.11
    jinja_environment = Environment

    #: The class that is used for the :data:`~flask.g` instance.
    #:
    #: Example use cases for a custom class:
    #:
    #: 1. Store arbitrary attributes on flask.g.
    #: 2. Add a property for lazy per-request database connectors.
    #: 3. Return None instead of AttributeError on unexpected attributes.
    #: 4. Raise exception if an unexpected attr is set, a "controlled" flask.g.
    #:
    #: In Flask 0.9 this property was called `request_globals_class` but it
    #: was changed in 0.10 to :attr:`app_ctx_globals_class` because the
    #: flask.g object is now application context scoped.
    #:
    #: .. versionadded:: 0.10
    app_ctx_globals_class = _AppCtxGlobals

    #: The class that is used for the ``config`` attribute of this app.
    #: Defaults to :class:`~flask.Config`.
    #:
    #: Example use cases for a custom class:
    #:
    #: 1. Default values for certain config options.
    #: 2. Access to config values through attributes in addition to keys.
    #:
    #: .. versionadded:: 0.11
    config_class = Config

    #: The testing flag.  Set this to ``True`` to enable the test mode of
    #: Flask extensions (and in the future probably also Flask itself).
    #: For example this might activate test helpers that have an
    #: additional runtime cost which should not be enabled by default.
    #:
    #: If this is enabled and PROPAGATE_EXCEPTIONS is not changed from the
    #: default it's implicitly enabled.
    #:
    #: This attribute can also be configured from the config with the
    #: ``TESTING`` configuration key.  Defaults to ``False``.
    testing = ConfigAttribute[bool]("TESTING")

    #: If a secret key is set, cryptographic components can use this to
    #: sign cookies and other things. Set this to a complex random value
    #: when you want to use the secure cookie for instance.
    #:
    #: This attribute can also be configured from the config with the
    #: :data:`SECRET_KEY` configuration key. Defaults to ``None``.
    secret_key = ConfigAttribute[t.Union[str, bytes, None]]("SECRET_KEY")

    #: A :class:`~datetime.timedelta` which is used to set the expiration
    #: date of a permanent session.  The default is 31 days which makes a
    #: permanent session survive for roughly one month.
    #:
    #: This attribute can also be configured from the config with the
    #: ``PERMANENT_SESSION_LIFETIME`` configuration key.  Defaults to
    #: ``timedelta(days=31)``
    permanent_session_lifetime = ConfigAttribute[timedelta](
        "PERMANENT_SESSION_LIFETIME",
        get_converter=_make_timedelta,  # type: ignore[arg-type]
    )

    json_provider_class: type[JSONProvider] = DefaultJSONProvider
    """A subclass of :class:`~flask.json.provider.JSONProvider`. An
    instance is created and assigned to :attr:`app.json` when creating
    the app.

    The default, :class:`~flask.json.provider.DefaultJSONProvider`, uses
    Python's built-in :mod:`json` library. A different provider can use
    a different JSON library.

    .. versionadded:: 2.2
    """

    #: Options that are passed to the Jinja environment in
    #: :meth:`create_jinja_environment`. Changing these options after
    #: the environment is created (accessing :attr:`jinja_env`) will
    #: have no effect.
    #:
    #: .. versionchanged:: 1.1.0
    #:     This is a ``dict`` instead of an ``ImmutableDict`` to allow
    #:     easier configuration.
    #:
    jinja_options: dict[str, t.Any] = {}

    #: The rule object to use for URL rules created.  This is used by
    #: :meth:`add_url_rule`.  Defaults to :class:`werkzeug.routing.Rule`.
    #:
    #: .. versionadded:: 0.7
    url_rule_class = Rule

    #: The map object to use for storing the URL rules and routing
    #: configuration parameters. Defaults to :class:`werkzeug.routing.Map`.
    #:
    #: .. versionadded:: 1.1.0
    url_map_class = Map

    #: The :meth:`test_client` method creates an instance of this test
    #: client class. Defaults to :class:`~flask.testing.FlaskClient`.
    #:
    #: .. versionadded:: 0.7
    test_client_class: type[FlaskClient] | None = None

    #: The :class:`~click.testing.CliRunner` subclass, by default
    #: :class:`~flask.testing.FlaskCliRunner` that is used by
    #: :meth:`test_cli_runner`. Its ``__init__`` method should take a
    #: Flask app object as the first argument.
    #:
    #: .. versionadded:: 1.0
    test_cli_runner_class: type[FlaskCliRunner] | None = None

    default_config: dict[str, t.Any]
    response_class: type[Response]

    def __init__(
        self,
        import_name: str,
        static_url_path: str | None = None,
        static_folder: str | os.PathLike[str] | None = "static",
        static_host: str | None = None,
        host_matching: bool = False,
        subdomain_matching: bool = False,
        template_folder: str | os.PathLike[str] | None = "templates",
        instance_path: str | None = None,
        instance_relative_config: bool = False,
        root_path: str | None = None,
    ):
        super().__init__(
            import_name=import_name,
            static_folder=static_folder,
            static_url_path=static_url_path,
            template_folder=template_folder,
            root_path=root_path,
        )

        if instance_path is None:
            instance_path = self.auto_find_instance_path()
        elif not os.path.isabs(instance_path):
            raise ValueError(
                "If an instance path is provided it must be absolute."
                " A relative path was given instead."
            )

        #: Holds the path to the instance folder.
        #:
        #: .. versionadded:: 0.8
        self.instance_path = instance_path

        #: The configuration dictionary as :class:`Config`.  This behaves
        #: exactly like a regular dictionary but supports additional methods
        #: to load a config from files.
        self.config = self.make_config(instance_relative_config)

        #: An instance of :attr:`aborter_class` created by
        #: :meth:`make_aborter`. This is called by :func:`flask.abort`
        #: to raise HTTP errors, and can be called directly as well.
        #:
        #: .. versionadded:: 2.2
        #:     Moved from ``flask.abort``, which calls this object.
        self.aborter = self.make_aborter()

        self.json: JSONProvider = self.json_provider_class(self)
        """Provides access to JSON methods. Functions in ``flask.json``
        will call methods on this provider when the application context
        is active. Used for handling JSON requests and responses.

        An instance of :attr:`json_provider_class`. Can be customized by
        changing that attribute on a subclass, or by assigning to this
        attribute afterwards.

        The default, :class:`~flask.json.provider.DefaultJSONProvider`,
        uses Python's built-in :mod:`json` library. A different provider
        can use a different JSON library.

        .. versionadded:: 2.2
        """

        #: A list of functions that are called by
        #: :meth:`handle_url_build_error` when :meth:`.url_for` raises a
        #: :exc:`~werkzeug.routing.BuildError`. Each function is called
        #: with ``error``, ``endpoint`` and ``values``. If a function
        #: returns ``None`` or raises a ``BuildError``, it is skipped.
        #: Otherwise, its return value is returned by ``url_for``.
        #:
        #: .. versionadded:: 0.9
        self.url_build_error_handlers: list[
            t.Callable[[Exception, str, dict[str, t.Any]], str]
        ] = []

        #: A list of functions that are called when the application context
        #: is destroyed.  Since the application context is also torn down
        #: if the request ends this is the place to store code that disconnects
        #: from databases.
        #:
        #: .. versionadded:: 0.9
        self.teardown_appcontext_funcs: list[ft.TeardownCallable] = []

        #: A list of shell context processor functions that should be run
        #: when a shell context is created.
        #:
        #: .. versionadded:: 0.11
        self.shell_context_processors: list[ft.ShellContextProcessorCallable] = []

        #: Maps registered blueprint names to blueprint objects. The
        #: dict retains the order the blueprints were registered in.
        #: Blueprints can be registered multiple times, this dict does
        #: not track how often they were attached.
        #:
        #: .. versionadded:: 0.7
        self.blueprints: dict[str, Blueprint] = {}

        #: a place where extensions can store application specific state.  For
        #: example this is where an extension could store database engines and
        #: similar things.
        #:
        #: The key must match the name of the extension module. For example in
        #: case of a "Flask-Foo" extension in `flask_foo`, the key would be
        #: ``'foo'``.
        #:
        #: .. versionadded:: 0.7
        self.extensions: dict[str, t.Any] = {}

        #: The :class:`~werkzeug.routing.Map` for this instance.  You can use
        #: this to change the routing converters after the class was created
        #: but before any routes are connected.  Example::
        #:
        #:    from werkzeug.routing import BaseConverter
        #:
        #:    class ListConverter(BaseConverter):
        #:        def to_python(self, value):
        #:            return value.split(',')
        #:        def to_url(self, values):
        #:            return ','.join(super(ListConverter, self).to_url(value)
        #:                            for value in values)
        #:
        #:    app = Flask(__name__)
        #:    app.url_map.converters['list'] = ListConverter
        self.url_map = self.url_map_class(host_matching=host_matching)

        self.subdomain_matching = subdomain_matching

        # tracks internally if the application already handled at least one
        # request.
        self._got_first_request = False

        # Set the name of the Click group in case someone wants to add
        # the app's commands to another CLI tool.
        self.cli.name = self.name

    def _check_setup_finished(self, f_name: str) -> None:
        if self._got_first_request:
            raise AssertionError(
                f"The setup method '{f_name}' can no longer be called"
                " on the application. It has already handled its first"
                " request, any changes will not be applied"
                " consistently.\n"
                "Make sure all imports, decorators, functions, etc."
                " needed to set up the application are done before"
                " running it."
            )

    @cached_property
    def name(self) -> str:  # type: ignore
        """The name of the application.  This is usually the import name
        with the difference that it's guessed from the run file if the
        import name is main.  This name is used as a display name when
        Flask needs the name of the application.  It can be set and overridden
        to change the value.

        .. versionadded:: 0.8
        """
        if self.import_name == "__main__":
            fn: str | None = getattr(sys.modules["__main__"], "__file__", None)
            if fn is None:
                return "__main__"
            return os.path.splitext(os.path.basename(fn))[0]
        return self.import_name

    @cached_property
    def logger(self) -> logging.Logger:
        """A standard Python :class:`~logging.Logger` for the app, with
        the same name as :attr:`name`.

        In debug mode, the logger's :attr:`~logging.Logger.level` will
        be set to :data:`~logging.DEBUG`.

        If there are no handlers configured, a default handler will be
        added. See :doc:`/logging` for more information.

        .. versionchanged:: 1.1.0
            The logger takes the same name as :attr:`name` rather than
            hard-coding ``"flask.app"``.

        .. versionchanged:: 1.0.0
            Behavior was simplified. The logger is always named
            ``"flask.app"``. The level is only set during configuration,
            it doesn't check ``app.debug`` each time. Only one format is
            used, not different ones depending on ``app.debug``. No
            handlers are removed, and a handler is only added if no
            handlers are already configured.

        .. versionadded:: 0.3
        """
        return create_logger(self)

    @cached_property
    def jinja_env(self) -> Environment:
        """The Jinja environment used to load templates.

        The environment is created the first time this property is
        accessed. Changing :attr:`jinja_options` after that will have no
        effect.
        """
        return self.create_jinja_environment()

    def create_jinja_environment(self) -> Environment:
        raise NotImplementedError()

    def make_config(self, instance_relative: bool = False) -> Config:
        """Used to create the config attribute by the Flask constructor.
        The `instance_relative` parameter is passed in from the constructor
        of Flask (there named `instance_relative_config`) and indicates if
        the config should be relative to the instance path or the root path
        of the application.

        .. versionadded:: 0.8
        """
        root_path = self.root_path
        if instance_relative:
            root_path = self.instance_path
        defaults = dict(self.default_config)
        defaults["DEBUG"] = get_debug_flag()
        return self.config_class(root_path, defaults)

    def make_aborter(self) -> Aborter:
        """Create the object to assign to :attr:`aborter`. That object
        is called by :func:`flask.abort` to raise HTTP errors, and can
        be called directly as well.

        By default, this creates an instance of :attr:`aborter_class`,
        which defaults to :class:`werkzeug.exceptions.Aborter`.

        .. versionadded:: 2.2
        """
        return self.aborter_class()

    def auto_find_instance_path(self) -> str:
        """Tries to locate the instance path if it was not provided to the
        constructor of the application class.  It will basically calculate
        the path to a folder named ``instance`` next to your main file or
        the package.

        .. versionadded:: 0.8
        """
        prefix, package_path = find_package(self.import_name)
        if prefix is None:
            return os.path.join(package_path, "instance")
        return os.path.join(prefix, "var", f"{self.name}-instance")

    def create_global_jinja_loader(self) -> DispatchingJinjaLoader:
        """Creates the loader for the Jinja2 environment.  Can be used to
        override just the loader and keeping the rest unchanged.  It's
        discouraged to override this function.  Instead one should override
        the :meth:`jinja_loader` function instead.

        The global loader dispatches between the loaders of the application
        and the individual blueprints.

        .. versionadded:: 0.7
        """
        return DispatchingJinjaLoader(self)

    def select_jinja_autoescape(self, filename: str) -> bool:
        """Returns ``True`` if autoescaping should be active for the given
        template name. If no template name is given, returns `True`.

        .. versionchanged:: 2.2
            Autoescaping is now enabled by default for ``.svg`` files.

        .. versionadded:: 0.5
        """
        if filename is None:
            return True
        return filename.endswith((".html", ".htm", ".xml", ".xhtml", ".svg"))

    @property
    def debug(self) -> bool:
        """Whether debug mode is enabled. When using ``flask run`` to start the
        development server, an interactive debugger will be shown for unhandled
        exceptions, and the server will be reloaded when code changes. This maps to the
        :data:`DEBUG` config key. It may not behave as expected if set late.

        **Do not enable debug mode when deploying in production.**

        Default: ``False``
        """
        return self.config["DEBUG"]  # type: ignore[no-any-return]

    @debug.setter
    def debug(self, value: bool) -> None:
        self.config["DEBUG"] = value

        if self.config["TEMPLATES_AUTO_RELOAD"] is None:
            self.jinja_env.auto_reload = value

    @setupmethod
    def register_blueprint(self, blueprint: Blueprint, **options: t.Any) -> None:
        """Register a :class:`~flask.Blueprint` on the application. Keyword
        arguments passed to this method will override the defaults set on the
        blueprint.

        Calls the blueprint's :meth:`~flask.Blueprint.register` method after
        recording the blueprint in the application's :attr:`blueprints`.

        :param blueprint: The blueprint to register.
        :param url_prefix: Blueprint routes will be prefixed with this.
        :param subdomain: Blueprint routes will match on this subdomain.
        :param url_defaults: Blueprint routes will use these default values for
            view arguments.
        :param options: Additional keyword arguments are passed to
            :class:`~flask.blueprints.BlueprintSetupState`. They can be
            accessed in :meth:`~flask.Blueprint.record` callbacks.

        .. versionchanged:: 2.0.1
            The ``name`` option can be used to change the (pre-dotted)
            name the blueprint is registered with. This allows the same
            blueprint to be registered multiple times with unique names
            for ``url_for``.

        .. versionadded:: 0.7
        """
        blueprint.register(self, options)

    def iter_blueprints(self) -> t.ValuesView[Blueprint]:
        """Iterates over all blueprints by the order they were registered.

        .. versionadded:: 0.11
        """
        return self.blueprints.values()

    @setupmethod
    def add_url_rule(
        self,
        rule: str,
        endpoint: str | None = None,
        view_func: ft.RouteCallable | None = None,
        provide_automatic_options: bool | None = None,
        **options: t.Any,
    ) -> None:
        if endpoint is None:
            endpoint = _endpoint_from_view_func(view_func)  # type: ignore
        options["endpoint"] = endpoint
        methods = options.pop("methods", None)

        # if the methods are not given and the view_func object knows its
        # methods we can use that instead.  If neither exists, we go with
        # a tuple of only ``GET`` as default.
        if methods is None:
            methods = getattr(view_func, "methods", None) or ("GET",)
        if isinstance(methods, str):
            raise TypeError(
                "Allowed methods must be a list of strings, for"
                ' example: @app.route(..., methods=["POST"])'
            )
        methods = {item.upper() for item in methods}

        # Methods that should always be added
        required_methods = set(getattr(view_func, "required_methods", ()))

        # starting with Flask 0.8 the view_func object can disable and
        # force-enable the automatic options handling.
        if provide_automatic_options is None:
            provide_automatic_options = getattr(
                view_func, "provide_automatic_options", None
            )

        if provide_automatic_options is None:
            if "OPTIONS" not in methods:
                provide_automatic_options = True
                required_methods.add("OPTIONS")
            else:
                provide_automatic_options = False

        # Add the required methods now.
        methods |= required_methods

        rule_obj = self.url_rule_class(rule, methods=methods, **options)
        rule_obj.provide_automatic_options = provide_automatic_options  # type: ignore[attr-defined]

        self.url_map.add(rule_obj)
        if view_func is not None:
            old_func = self.view_functions.get(endpoint)
            if old_func is not None and old_func != view_func:
                raise AssertionError(
                    "View function mapping is overwriting an existing"
                    f" endpoint function: {endpoint}"
                )
            self.view_functions[endpoint] = view_func

    @setupmethod
    def template_filter(
        self, name: str | None = None
    ) -> t.Callable[[T_template_filter], T_template_filter]:
        """A decorator that is used to register custom template filter.
        You can specify a name for the filter, otherwise the function
        name will be used. Example::

          @app.template_filter()
          def reverse(s):
              return s[::-1]

        :param name: the optional name of the filter, otherwise the
                     function name will be used.
        """

        def decorator(f: T_template_filter) -> T_template_filter:
            self.add_template_filter(f, name=name)
            return f

        return decorator

    @setupmethod
    def add_template_filter(
        self, f: ft.TemplateFilterCallable, name: str | None = None
    ) -> None:
        """Register a custom template filter.  Works exactly like the
        :meth:`template_filter` decorator.

        :param name: the optional name of the filter, otherwise the
                     function name will be used.
        """
        self.jinja_env.filters[name or f.__name__] = f

    @setupmethod
    def template_test(
        self, name: str | None = None
    ) -> t.Callable[[T_template_test], T_template_test]:
        """A decorator that is used to register custom template test.
        You can specify a name for the test, otherwise the function
        name will be used. Example::

          @app.template_test()
          def is_prime(n):
              if n == 2:
                  return True
              for i in range(2, int(math.ceil(math.sqrt(n))) + 1):
                  if n % i == 0:
                      return False
              return True

        .. versionadded:: 0.10

        :param name: the optional name of the test, otherwise the
                     function name will be used.
        """

        def decorator(f: T_template_test) -> T_template_test:
            self.add_template_test(f, name=name)
            return f

        return decorator

    @setupmethod
    def add_template_test(
        self, f: ft.TemplateTestCallable, name: str | None = None
    ) -> None:
        """Register a custom template test.  Works exactly like the
        :meth:`template_test` decorator.

        .. versionadded:: 0.10

        :param name: the optional name of the test, otherwise the
                     function name will be used.
        """
        self.jinja_env.tests[name or f.__name__] = f

    @setupmethod
    def template_global(
        self, name: str | None = None
    ) -> t.Callable[[T_template_global], T_template_global]:
        """A decorator that is used to register a custom template global function.
        You can specify a name for the global function, otherwise the function
        name will be used. Example::

            @app.template_global()
            def double(n):
                return 2 * n

        .. versionadded:: 0.10

        :param name: the optional name of the global function, otherwise the
                     function name will be used.
        """

        def decorator(f: T_template_global) -> T_template_global:
            self.add_template_global(f, name=name)
            return f

        return decorator

    @setupmethod
    def add_template_global(
        self, f: ft.TemplateGlobalCallable, name: str | None = None
    ) -> None:
        """Register a custom template global function. Works exactly like the
        :meth:`template_global` decorator.

        .. versionadded:: 0.10

        :param name: the optional name of the global function, otherwise the
                     function name will be used.
        """
        self.jinja_env.globals[name or f.__name__] = f

    @setupmethod
    def teardown_appcontext(self, f: T_teardown) -> T_teardown:
        """Registers a function to be called when the application
        context is popped. The application context is typically popped
        after the request context for each request, at the end of CLI
        commands, or after a manually pushed context ends.

        .. code-block:: python

            with app.app_context():
                ...

        When the ``with`` block exits (or ``ctx.pop()`` is called), the
        teardown functions are called just before the app context is
        made inactive. Since a request context typically also manages an
        application context it would also be called when you pop a
        request context.

        When a teardown function was called because of an unhandled
        exception it will be passed an error object. If an
        :meth:`errorhandler` is registered, it will handle the exception
        and the teardown will not receive it.

        Teardown functions must avoid raising exceptions. If they
        execute code that might fail they must surround that code with a
        ``try``/``except`` block and log any errors.

        The return values of teardown functions are ignored.

        .. versionadded:: 0.9
        """
        self.teardown_appcontext_funcs.append(f)
        return f

    @setupmethod
    def shell_context_processor(
        self, f: T_shell_context_processor
    ) -> T_shell_context_processor:
        """Registers a shell context processor function.

        .. versionadded:: 0.11
        """
        self.shell_context_processors.append(f)
        return f

    def _find_error_handler(
        self, e: Exception, blueprints: list[str]
    ) -> ft.ErrorHandlerCallable | None:
        """Return a registered error handler for an exception in this order:
        blueprint handler for a specific code, app handler for a specific code,
        blueprint handler for an exception class, app handler for an exception
        class, or ``None`` if a suitable handler is not found.
        """
        exc_class, code = self._get_exc_class_and_code(type(e))
        names = (*blueprints, None)

        for c in (code, None) if code is not None else (None,):
            for name in names:
                handler_map = self.error_handler_spec[name][c]

                if not handler_map:
                    continue

                for cls in exc_class.__mro__:
                    handler = handler_map.get(cls)

                    if handler is not None:
                        return handler
        return None

    def trap_http_exception(self, e: Exception) -> bool:
        """Checks if an HTTP exception should be trapped or not.  By default
        this will return ``False`` for all exceptions except for a bad request
        key error if ``TRAP_BAD_REQUEST_ERRORS`` is set to ``True``.  It
        also returns ``True`` if ``TRAP_HTTP_EXCEPTIONS`` is set to ``True``.

        This is called for all HTTP exceptions raised by a view function.
        If it returns ``True`` for any exception the error handler for this
        exception is not called and it shows up as regular exception in the
        traceback.  This is helpful for debugging implicitly raised HTTP
        exceptions.

        .. versionchanged:: 1.0
            Bad request errors are not trapped by default in debug mode.

        .. versionadded:: 0.8
        """
        if self.config["TRAP_HTTP_EXCEPTIONS"]:
            return True

        trap_bad_request = self.config["TRAP_BAD_REQUEST_ERRORS"]

        # if unset, trap key errors in debug mode
        if (
            trap_bad_request is None
            and self.debug
            and isinstance(e, BadRequestKeyError)
        ):
            return True

        if trap_bad_request:
            return isinstance(e, BadRequest)

        return False

    def should_ignore_error(self, error: BaseException | None) -> bool:
        """This is called to figure out if an error should be ignored
        or not as far as the teardown system is concerned.  If this
        function returns ``True`` then the teardown handlers will not be
        passed the error.

        .. versionadded:: 0.10
        """
        return False

    def redirect(self, location: str, code: int = 302) -> BaseResponse:
        """Create a redirect response object.

        This is called by :func:`flask.redirect`, and can be called
        directly as well.

        :param location: The URL to redirect to.
        :param code: The status code for the redirect.

        .. versionadded:: 2.2
            Moved from ``flask.redirect``, which calls this method.
        """
        return _wz_redirect(
            location,
            code=code,
            Response=self.response_class,  # type: ignore[arg-type]
        )

    def inject_url_defaults(self, endpoint: str, values: dict[str, t.Any]) -> None:
        """Injects the URL defaults for the given endpoint directly into
        the values dictionary passed.  This is used internally and
        automatically called on URL building.

        .. versionadded:: 0.7
        """
        names: t.Iterable[str | None] = (None,)

        # url_for may be called outside a request context, parse the
        # passed endpoint instead of using request.blueprints.
        if "." in endpoint:
            names = chain(
                names, reversed(_split_blueprint_path(endpoint.rpartition(".")[0]))
            )

        for name in names:
            if name in self.url_default_functions:
                for func in self.url_default_functions[name]:
                    func(endpoint, values)

    def handle_url_build_error(
        self, error: BuildError, endpoint: str, values: dict[str, t.Any]
    ) -> str:
        """Called by :meth:`.url_for` if a
        :exc:`~werkzeug.routing.BuildError` was raised. If this returns
        a value, it will be returned by ``url_for``, otherwise the error
        will be re-raised.

        Each function in :attr:`url_build_error_handlers` is called with
        ``error``, ``endpoint`` and ``values``. If a function returns
        ``None`` or raises a ``BuildError``, it is skipped. Otherwise,
        its return value is returned by ``url_for``.

        :param error: The active ``BuildError`` being handled.
        :param endpoint: The endpoint being built.
        :param values: The keyword arguments passed to ``url_for``.
        """
        for handler in self.url_build_error_handlers:
            try:
                rv = handler(error, endpoint, values)
            except BuildError as e:
                # make error available outside except block
                error = e
            else:
                if rv is not None:
                    return rv

        # Re-raise if called with an active exception, otherwise raise
        # the passed in exception.
        if error is sys.exc_info()[1]:
            raise

        raise error


Filepath: githubCode\src\flask\sansio\blueprints.py:

from __future__ import annotations

import os
import typing as t
from collections import defaultdict
from functools import update_wrapper

from .. import typing as ft
from .scaffold import _endpoint_from_view_func
from .scaffold import _sentinel
from .scaffold import Scaffold
from .scaffold import setupmethod

if t.TYPE_CHECKING:  # pragma: no cover
    from .app import App

DeferredSetupFunction = t.Callable[["BlueprintSetupState"], None]
T_after_request = t.TypeVar("T_after_request", bound=ft.AfterRequestCallable[t.Any])
T_before_request = t.TypeVar("T_before_request", bound=ft.BeforeRequestCallable)
T_error_handler = t.TypeVar("T_error_handler", bound=ft.ErrorHandlerCallable)
T_teardown = t.TypeVar("T_teardown", bound=ft.TeardownCallable)
T_template_context_processor = t.TypeVar(
    "T_template_context_processor", bound=ft.TemplateContextProcessorCallable
)
T_template_filter = t.TypeVar("T_template_filter", bound=ft.TemplateFilterCallable)
T_template_global = t.TypeVar("T_template_global", bound=ft.TemplateGlobalCallable)
T_template_test = t.TypeVar("T_template_test", bound=ft.TemplateTestCallable)
T_url_defaults = t.TypeVar("T_url_defaults", bound=ft.URLDefaultCallable)
T_url_value_preprocessor = t.TypeVar(
    "T_url_value_preprocessor", bound=ft.URLValuePreprocessorCallable
)


class BlueprintSetupState:
    """Temporary holder object for registering a blueprint with the
    application.  An instance of this class is created by the
    :meth:`~flask.Blueprint.make_setup_state` method and later passed
    to all register callback functions.
    """

    def __init__(
        self,
        blueprint: Blueprint,
        app: App,
        options: t.Any,
        first_registration: bool,
    ) -> None:
        #: a reference to the current application
        self.app = app

        #: a reference to the blueprint that created this setup state.
        self.blueprint = blueprint

        #: a dictionary with all options that were passed to the
        #: :meth:`~flask.Flask.register_blueprint` method.
        self.options = options

        #: as blueprints can be registered multiple times with the
        #: application and not everything wants to be registered
        #: multiple times on it, this attribute can be used to figure
        #: out if the blueprint was registered in the past already.
        self.first_registration = first_registration

        subdomain = self.options.get("subdomain")
        if subdomain is None:
            subdomain = self.blueprint.subdomain

        #: The subdomain that the blueprint should be active for, ``None``
        #: otherwise.
        self.subdomain = subdomain

        url_prefix = self.options.get("url_prefix")
        if url_prefix is None:
            url_prefix = self.blueprint.url_prefix
        #: The prefix that should be used for all URLs defined on the
        #: blueprint.
        self.url_prefix = url_prefix

        self.name = self.options.get("name", blueprint.name)
        self.name_prefix = self.options.get("name_prefix", "")

        #: A dictionary with URL defaults that is added to each and every
        #: URL that was defined with the blueprint.
        self.url_defaults = dict(self.blueprint.url_values_defaults)
        self.url_defaults.update(self.options.get("url_defaults", ()))

    def add_url_rule(
        self,
        rule: str,
        endpoint: str | None = None,
        view_func: ft.RouteCallable | None = None,
        **options: t.Any,
    ) -> None:
        """A helper method to register a rule (and optionally a view function)
        to the application.  The endpoint is automatically prefixed with the
        blueprint's name.
        """
        if self.url_prefix is not None:
            if rule:
                rule = "/".join((self.url_prefix.rstrip("/"), rule.lstrip("/")))
            else:
                rule = self.url_prefix
        options.setdefault("subdomain", self.subdomain)
        if endpoint is None:
            endpoint = _endpoint_from_view_func(view_func)  # type: ignore
        defaults = self.url_defaults
        if "defaults" in options:
            defaults = dict(defaults, **options.pop("defaults"))

        self.app.add_url_rule(
            rule,
            f"{self.name_prefix}.{self.name}.{endpoint}".lstrip("."),
            view_func,
            defaults=defaults,
            **options,
        )


class Blueprint(Scaffold):
    """Represents a blueprint, a collection of routes and other
    app-related functions that can be registered on a real application
    later.

    A blueprint is an object that allows defining application functions
    without requiring an application object ahead of time. It uses the
    same decorators as :class:`~flask.Flask`, but defers the need for an
    application by recording them for later registration.

    Decorating a function with a blueprint creates a deferred function
    that is called with :class:`~flask.blueprints.BlueprintSetupState`
    when the blueprint is registered on an application.

    See :doc:`/blueprints` for more information.

    :param name: The name of the blueprint. Will be prepended to each
        endpoint name.
    :param import_name: The name of the blueprint package, usually
        ``__name__``. This helps locate the ``root_path`` for the
        blueprint.
    :param static_folder: A folder with static files that should be
        served by the blueprint's static route. The path is relative to
        the blueprint's root path. Blueprint static files are disabled
        by default.
    :param static_url_path: The url to serve static files from.
        Defaults to ``static_folder``. If the blueprint does not have
        a ``url_prefix``, the app's static route will take precedence,
        and the blueprint's static files won't be accessible.
    :param template_folder: A folder with templates that should be added
        to the app's template search path. The path is relative to the
        blueprint's root path. Blueprint templates are disabled by
        default. Blueprint templates have a lower precedence than those
        in the app's templates folder.
    :param url_prefix: A path to prepend to all of the blueprint's URLs,
        to make them distinct from the rest of the app's routes.
    :param subdomain: A subdomain that blueprint routes will match on by
        default.
    :param url_defaults: A dict of default values that blueprint routes
        will receive by default.
    :param root_path: By default, the blueprint will automatically set
        this based on ``import_name``. In certain situations this
        automatic detection can fail, so the path can be specified
        manually instead.

    .. versionchanged:: 1.1.0
        Blueprints have a ``cli`` group to register nested CLI commands.
        The ``cli_group`` parameter controls the name of the group under
        the ``flask`` command.

    .. versionadded:: 0.7
    """

    _got_registered_once = False

    def __init__(
        self,
        name: str,
        import_name: str,
        static_folder: str | os.PathLike[str] | None = None,
        static_url_path: str | None = None,
        template_folder: str | os.PathLike[str] | None = None,
        url_prefix: str | None = None,
        subdomain: str | None = None,
        url_defaults: dict[str, t.Any] | None = None,
        root_path: str | None = None,
        cli_group: str | None = _sentinel,  # type: ignore[assignment]
    ):
        super().__init__(
            import_name=import_name,
            static_folder=static_folder,
            static_url_path=static_url_path,
            template_folder=template_folder,
            root_path=root_path,
        )

        if not name:
            raise ValueError("'name' may not be empty.")

        if "." in name:
            raise ValueError("'name' may not contain a dot '.' character.")

        self.name = name
        self.url_prefix = url_prefix
        self.subdomain = subdomain
        self.deferred_functions: list[DeferredSetupFunction] = []

        if url_defaults is None:
            url_defaults = {}

        self.url_values_defaults = url_defaults
        self.cli_group = cli_group
        self._blueprints: list[tuple[Blueprint, dict[str, t.Any]]] = []

    def _check_setup_finished(self, f_name: str) -> None:
        if self._got_registered_once:
            raise AssertionError(
                f"The setup method '{f_name}' can no longer be called on the blueprint"
                f" '{self.name}'. It has already been registered at least once, any"
                " changes will not be applied consistently.\n"
                "Make sure all imports, decorators, functions, etc. needed to set up"
                " the blueprint are done before registering it."
            )

    @setupmethod
    def record(self, func: DeferredSetupFunction) -> None:
        """Registers a function that is called when the blueprint is
        registered on the application.  This function is called with the
        state as argument as returned by the :meth:`make_setup_state`
        method.
        """
        self.deferred_functions.append(func)

    @setupmethod
    def record_once(self, func: DeferredSetupFunction) -> None:
        """Works like :meth:`record` but wraps the function in another
        function that will ensure the function is only called once.  If the
        blueprint is registered a second time on the application, the
        function passed is not called.
        """

        def wrapper(state: BlueprintSetupState) -> None:
            if state.first_registration:
                func(state)

        self.record(update_wrapper(wrapper, func))

    def make_setup_state(
        self, app: App, options: dict[str, t.Any], first_registration: bool = False
    ) -> BlueprintSetupState:
        """Creates an instance of :meth:`~flask.blueprints.BlueprintSetupState`
        object that is later passed to the register callback functions.
        Subclasses can override this to return a subclass of the setup state.
        """
        return BlueprintSetupState(self, app, options, first_registration)

    @setupmethod
    def register_blueprint(self, blueprint: Blueprint, **options: t.Any) -> None:
        """Register a :class:`~flask.Blueprint` on this blueprint. Keyword
        arguments passed to this method will override the defaults set
        on the blueprint.

        .. versionchanged:: 2.0.1
            The ``name`` option can be used to change the (pre-dotted)
            name the blueprint is registered with. This allows the same
            blueprint to be registered multiple times with unique names
            for ``url_for``.

        .. versionadded:: 2.0
        """
        if blueprint is self:
            raise ValueError("Cannot register a blueprint on itself")
        self._blueprints.append((blueprint, options))

    def register(self, app: App, options: dict[str, t.Any]) -> None:
        """Called by :meth:`Flask.register_blueprint` to register all
        views and callbacks registered on the blueprint with the
        application. Creates a :class:`.BlueprintSetupState` and calls
        each :meth:`record` callback with it.

        :param app: The application this blueprint is being registered
            with.
        :param options: Keyword arguments forwarded from
            :meth:`~Flask.register_blueprint`.

        .. versionchanged:: 2.3
            Nested blueprints now correctly apply subdomains.

        .. versionchanged:: 2.1
            Registering the same blueprint with the same name multiple
            times is an error.

        .. versionchanged:: 2.0.1
            Nested blueprints are registered with their dotted name.
            This allows different blueprints with the same name to be
            nested at different locations.

        .. versionchanged:: 2.0.1
            The ``name`` option can be used to change the (pre-dotted)
            name the blueprint is registered with. This allows the same
            blueprint to be registered multiple times with unique names
            for ``url_for``.
        """
        name_prefix = options.get("name_prefix", "")
        self_name = options.get("name", self.name)
        name = f"{name_prefix}.{self_name}".lstrip(".")

        if name in app.blueprints:
            bp_desc = "this" if app.blueprints[name] is self else "a different"
            existing_at = f" '{name}'" if self_name != name else ""

            raise ValueError(
                f"The name '{self_name}' is already registered for"
                f" {bp_desc} blueprint{existing_at}. Use 'name=' to"
                f" provide a unique name."
            )

        first_bp_registration = not any(bp is self for bp in app.blueprints.values())
        first_name_registration = name not in app.blueprints

        app.blueprints[name] = self
        self._got_registered_once = True
        state = self.make_setup_state(app, options, first_bp_registration)

        if self.has_static_folder:
            state.add_url_rule(
                f"{self.static_url_path}/<path:filename>",
                view_func=self.send_static_file,  # type: ignore[attr-defined]
                endpoint="static",
            )

        # Merge blueprint data into parent.
        if first_bp_registration or first_name_registration:
            self._merge_blueprint_funcs(app, name)

        for deferred in self.deferred_functions:
            deferred(state)

        cli_resolved_group = options.get("cli_group", self.cli_group)

        if self.cli.commands:
            if cli_resolved_group is None:
                app.cli.commands.update(self.cli.commands)
            elif cli_resolved_group is _sentinel:
                self.cli.name = name
                app.cli.add_command(self.cli)
            else:
                self.cli.name = cli_resolved_group
                app.cli.add_command(self.cli)

        for blueprint, bp_options in self._blueprints:
            bp_options = bp_options.copy()
            bp_url_prefix = bp_options.get("url_prefix")
            bp_subdomain = bp_options.get("subdomain")

            if bp_subdomain is None:
                bp_subdomain = blueprint.subdomain

            if state.subdomain is not None and bp_subdomain is not None:
                bp_options["subdomain"] = bp_subdomain + "." + state.subdomain
            elif bp_subdomain is not None:
                bp_options["subdomain"] = bp_subdomain
            elif state.subdomain is not None:
                bp_options["subdomain"] = state.subdomain

            if bp_url_prefix is None:
                bp_url_prefix = blueprint.url_prefix

            if state.url_prefix is not None and bp_url_prefix is not None:
                bp_options["url_prefix"] = (
                    state.url_prefix.rstrip("/") + "/" + bp_url_prefix.lstrip("/")
                )
            elif bp_url_prefix is not None:
                bp_options["url_prefix"] = bp_url_prefix
            elif state.url_prefix is not None:
                bp_options["url_prefix"] = state.url_prefix

            bp_options["name_prefix"] = name
            blueprint.register(app, bp_options)

    def _merge_blueprint_funcs(self, app: App, name: str) -> None:
        def extend(
            bp_dict: dict[ft.AppOrBlueprintKey, list[t.Any]],
            parent_dict: dict[ft.AppOrBlueprintKey, list[t.Any]],
        ) -> None:
            for key, values in bp_dict.items():
                key = name if key is None else f"{name}.{key}"
                parent_dict[key].extend(values)

        for key, value in self.error_handler_spec.items():
            key = name if key is None else f"{name}.{key}"
            value = defaultdict(
                dict,
                {
                    code: {exc_class: func for exc_class, func in code_values.items()}
                    for code, code_values in value.items()
                },
            )
            app.error_handler_spec[key] = value

        for endpoint, func in self.view_functions.items():
            app.view_functions[endpoint] = func

        extend(self.before_request_funcs, app.before_request_funcs)
        extend(self.after_request_funcs, app.after_request_funcs)
        extend(
            self.teardown_request_funcs,
            app.teardown_request_funcs,
        )
        extend(self.url_default_functions, app.url_default_functions)
        extend(self.url_value_preprocessors, app.url_value_preprocessors)
        extend(self.template_context_processors, app.template_context_processors)

    @setupmethod
    def add_url_rule(
        self,
        rule: str,
        endpoint: str | None = None,
        view_func: ft.RouteCallable | None = None,
        provide_automatic_options: bool | None = None,
        **options: t.Any,
    ) -> None:
        """Register a URL rule with the blueprint. See :meth:`.Flask.add_url_rule` for
        full documentation.

        The URL rule is prefixed with the blueprint's URL prefix. The endpoint name,
        used with :func:`url_for`, is prefixed with the blueprint's name.
        """
        if endpoint and "." in endpoint:
            raise ValueError("'endpoint' may not contain a dot '.' character.")

        if view_func and hasattr(view_func, "__name__") and "." in view_func.__name__:
            raise ValueError("'view_func' name may not contain a dot '.' character.")

        self.record(
            lambda s: s.add_url_rule(
                rule,
                endpoint,
                view_func,
                provide_automatic_options=provide_automatic_options,
                **options,
            )
        )

    @setupmethod
    def app_template_filter(
        self, name: str | None = None
    ) -> t.Callable[[T_template_filter], T_template_filter]:
        """Register a template filter, available in any template rendered by the
        application. Equivalent to :meth:`.Flask.template_filter`.

        :param name: the optional name of the filter, otherwise the
                     function name will be used.
        """

        def decorator(f: T_template_filter) -> T_template_filter:
            self.add_app_template_filter(f, name=name)
            return f

        return decorator

    @setupmethod
    def add_app_template_filter(
        self, f: ft.TemplateFilterCallable, name: str | None = None
    ) -> None:
        """Register a template filter, available in any template rendered by the
        application. Works like the :meth:`app_template_filter` decorator. Equivalent to
        :meth:`.Flask.add_template_filter`.

        :param name: the optional name of the filter, otherwise the
                     function name will be used.
        """

        def register_template(state: BlueprintSetupState) -> None:
            state.app.jinja_env.filters[name or f.__name__] = f

        self.record_once(register_template)

    @setupmethod
    def app_template_test(
        self, name: str | None = None
    ) -> t.Callable[[T_template_test], T_template_test]:
        """Register a template test, available in any template rendered by the
        application. Equivalent to :meth:`.Flask.template_test`.

        .. versionadded:: 0.10

        :param name: the optional name of the test, otherwise the
                     function name will be used.
        """

        def decorator(f: T_template_test) -> T_template_test:
            self.add_app_template_test(f, name=name)
            return f

        return decorator

    @setupmethod
    def add_app_template_test(
        self, f: ft.TemplateTestCallable, name: str | None = None
    ) -> None:
        """Register a template test, available in any template rendered by the
        application. Works like the :meth:`app_template_test` decorator. Equivalent to
        :meth:`.Flask.add_template_test`.

        .. versionadded:: 0.10

        :param name: the optional name of the test, otherwise the
                     function name will be used.
        """

        def register_template(state: BlueprintSetupState) -> None:
            state.app.jinja_env.tests[name or f.__name__] = f

        self.record_once(register_template)

    @setupmethod
    def app_template_global(
        self, name: str | None = None
    ) -> t.Callable[[T_template_global], T_template_global]:
        """Register a template global, available in any template rendered by the
        application. Equivalent to :meth:`.Flask.template_global`.

        .. versionadded:: 0.10

        :param name: the optional name of the global, otherwise the
                     function name will be used.
        """

        def decorator(f: T_template_global) -> T_template_global:
            self.add_app_template_global(f, name=name)
            return f

        return decorator

    @setupmethod
    def add_app_template_global(
        self, f: ft.TemplateGlobalCallable, name: str | None = None
    ) -> None:
        """Register a template global, available in any template rendered by the
        application. Works like the :meth:`app_template_global` decorator. Equivalent to
        :meth:`.Flask.add_template_global`.

        .. versionadded:: 0.10

        :param name: the optional name of the global, otherwise the
                     function name will be used.
        """

        def register_template(state: BlueprintSetupState) -> None:
            state.app.jinja_env.globals[name or f.__name__] = f

        self.record_once(register_template)

    @setupmethod
    def before_app_request(self, f: T_before_request) -> T_before_request:
        """Like :meth:`before_request`, but before every request, not only those handled
        by the blueprint. Equivalent to :meth:`.Flask.before_request`.
        """
        self.record_once(
            lambda s: s.app.before_request_funcs.setdefault(None, []).append(f)
        )
        return f

    @setupmethod
    def after_app_request(self, f: T_after_request) -> T_after_request:
        """Like :meth:`after_request`, but after every request, not only those handled
        by the blueprint. Equivalent to :meth:`.Flask.after_request`.
        """
        self.record_once(
            lambda s: s.app.after_request_funcs.setdefault(None, []).append(f)
        )
        return f

    @setupmethod
    def teardown_app_request(self, f: T_teardown) -> T_teardown:
        """Like :meth:`teardown_request`, but after every request, not only those
        handled by the blueprint. Equivalent to :meth:`.Flask.teardown_request`.
        """
        self.record_once(
            lambda s: s.app.teardown_request_funcs.setdefault(None, []).append(f)
        )
        return f

    @setupmethod
    def app_context_processor(
        self, f: T_template_context_processor
    ) -> T_template_context_processor:
        """Like :meth:`context_processor`, but for templates rendered by every view, not
        only by the blueprint. Equivalent to :meth:`.Flask.context_processor`.
        """
        self.record_once(
            lambda s: s.app.template_context_processors.setdefault(None, []).append(f)
        )
        return f

    @setupmethod
    def app_errorhandler(
        self, code: type[Exception] | int
    ) -> t.Callable[[T_error_handler], T_error_handler]:
        """Like :meth:`errorhandler`, but for every request, not only those handled by
        the blueprint. Equivalent to :meth:`.Flask.errorhandler`.
        """

        def decorator(f: T_error_handler) -> T_error_handler:
            def from_blueprint(state: BlueprintSetupState) -> None:
                state.app.errorhandler(code)(f)

            self.record_once(from_blueprint)
            return f

        return decorator

    @setupmethod
    def app_url_value_preprocessor(
        self, f: T_url_value_preprocessor
    ) -> T_url_value_preprocessor:
        """Like :meth:`url_value_preprocessor`, but for every request, not only those
        handled by the blueprint. Equivalent to :meth:`.Flask.url_value_preprocessor`.
        """
        self.record_once(
            lambda s: s.app.url_value_preprocessors.setdefault(None, []).append(f)
        )
        return f

    @setupmethod
    def app_url_defaults(self, f: T_url_defaults) -> T_url_defaults:
        """Like :meth:`url_defaults`, but for every request, not only those handled by
        the blueprint. Equivalent to :meth:`.Flask.url_defaults`.
        """
        self.record_once(
            lambda s: s.app.url_default_functions.setdefault(None, []).append(f)
        )
        return f


Filepath: githubCode\src\flask\sansio\scaffold.py:

from __future__ import annotations

import importlib.util
import os
import pathlib
import sys
import typing as t
from collections import defaultdict
from functools import update_wrapper

import click
from jinja2 import BaseLoader
from jinja2 import FileSystemLoader
from werkzeug.exceptions import default_exceptions
from werkzeug.exceptions import HTTPException
from werkzeug.utils import cached_property

from .. import typing as ft
from ..cli import AppGroup
from ..helpers import get_root_path
from ..templating import _default_template_ctx_processor

# a singleton sentinel value for parameter defaults
_sentinel = object()

F = t.TypeVar("F", bound=t.Callable[..., t.Any])
T_after_request = t.TypeVar("T_after_request", bound=ft.AfterRequestCallable[t.Any])
T_before_request = t.TypeVar("T_before_request", bound=ft.BeforeRequestCallable)
T_error_handler = t.TypeVar("T_error_handler", bound=ft.ErrorHandlerCallable)
T_teardown = t.TypeVar("T_teardown", bound=ft.TeardownCallable)
T_template_context_processor = t.TypeVar(
    "T_template_context_processor", bound=ft.TemplateContextProcessorCallable
)
T_url_defaults = t.TypeVar("T_url_defaults", bound=ft.URLDefaultCallable)
T_url_value_preprocessor = t.TypeVar(
    "T_url_value_preprocessor", bound=ft.URLValuePreprocessorCallable
)
T_route = t.TypeVar("T_route", bound=ft.RouteCallable)


def setupmethod(f: F) -> F:
    f_name = f.__name__

    def wrapper_func(self: Scaffold, *args: t.Any, **kwargs: t.Any) -> t.Any:
        self._check_setup_finished(f_name)
        return f(self, *args, **kwargs)

    return t.cast(F, update_wrapper(wrapper_func, f))


class Scaffold:
    """Common behavior shared between :class:`~flask.Flask` and
    :class:`~flask.blueprints.Blueprint`.

    :param import_name: The import name of the module where this object
        is defined. Usually :attr:`__name__` should be used.
    :param static_folder: Path to a folder of static files to serve.
        If this is set, a static route will be added.
    :param static_url_path: URL prefix for the static route.
    :param template_folder: Path to a folder containing template files.
        for rendering. If this is set, a Jinja loader will be added.
    :param root_path: The path that static, template, and resource files
        are relative to. Typically not set, it is discovered based on
        the ``import_name``.

    .. versionadded:: 2.0
    """

    name: str
    _static_folder: str | None = None
    _static_url_path: str | None = None

    def __init__(
        self,
        import_name: str,
        static_folder: str | os.PathLike[str] | None = None,
        static_url_path: str | None = None,
        template_folder: str | os.PathLike[str] | None = None,
        root_path: str | None = None,
    ):
        #: The name of the package or module that this object belongs
        #: to. Do not change this once it is set by the constructor.
        self.import_name = import_name

        self.static_folder = static_folder  # type: ignore
        self.static_url_path = static_url_path

        #: The path to the templates folder, relative to
        #: :attr:`root_path`, to add to the template loader. ``None`` if
        #: templates should not be added.
        self.template_folder = template_folder

        if root_path is None:
            root_path = get_root_path(self.import_name)

        #: Absolute path to the package on the filesystem. Used to look
        #: up resources contained in the package.
        self.root_path = root_path

        #: The Click command group for registering CLI commands for this
        #: object. The commands are available from the ``flask`` command
        #: once the application has been discovered and blueprints have
        #: been registered.
        self.cli: click.Group = AppGroup()

        #: A dictionary mapping endpoint names to view functions.
        #:
        #: To register a view function, use the :meth:`route` decorator.
        #:
        #: This data structure is internal. It should not be modified
        #: directly and its format may change at any time.
        self.view_functions: dict[str, ft.RouteCallable] = {}

        #: A data structure of registered error handlers, in the format
        #: ``{scope: {code: {class: handler}}}``. The ``scope`` key is
        #: the name of a blueprint the handlers are active for, or
        #: ``None`` for all requests. The ``code`` key is the HTTP
        #: status code for ``HTTPException``, or ``None`` for
        #: other exceptions. The innermost dictionary maps exception
        #: classes to handler functions.
        #:
        #: To register an error handler, use the :meth:`errorhandler`
        #: decorator.
        #:
        #: This data structure is internal. It should not be modified
        #: directly and its format may change at any time.
        self.error_handler_spec: dict[
            ft.AppOrBlueprintKey,
            dict[int | None, dict[type[Exception], ft.ErrorHandlerCallable]],
        ] = defaultdict(lambda: defaultdict(dict))

        #: A data structure of functions to call at the beginning of
        #: each request, in the format ``{scope: [functions]}``. The
        #: ``scope`` key is the name of a blueprint the functions are
        #: active for, or ``None`` for all requests.
        #:
        #: To register a function, use the :meth:`before_request`
        #: decorator.
        #:
        #: This data structure is internal. It should not be modified
        #: directly and its format may change at any time.
        self.before_request_funcs: dict[
            ft.AppOrBlueprintKey, list[ft.BeforeRequestCallable]
        ] = defaultdict(list)

        #: A data structure of functions to call at the end of each
        #: request, in the format ``{scope: [functions]}``. The
        #: ``scope`` key is the name of a blueprint the functions are
        #: active for, or ``None`` for all requests.
        #:
        #: To register a function, use the :meth:`after_request`
        #: decorator.
        #:
        #: This data structure is internal. It should not be modified
        #: directly and its format may change at any time.
        self.after_request_funcs: dict[
            ft.AppOrBlueprintKey, list[ft.AfterRequestCallable[t.Any]]
        ] = defaultdict(list)

        #: A data structure of functions to call at the end of each
        #: request even if an exception is raised, in the format
        #: ``{scope: [functions]}``. The ``scope`` key is the name of a
        #: blueprint the functions are active for, or ``None`` for all
        #: requests.
        #:
        #: To register a function, use the :meth:`teardown_request`
        #: decorator.
        #:
        #: This data structure is internal. It should not be modified
        #: directly and its format may change at any time.
        self.teardown_request_funcs: dict[
            ft.AppOrBlueprintKey, list[ft.TeardownCallable]
        ] = defaultdict(list)

        #: A data structure of functions to call to pass extra context
        #: values when rendering templates, in the format
        #: ``{scope: [functions]}``. The ``scope`` key is the name of a
        #: blueprint the functions are active for, or ``None`` for all
        #: requests.
        #:
        #: To register a function, use the :meth:`context_processor`
        #: decorator.
        #:
        #: This data structure is internal. It should not be modified
        #: directly and its format may change at any time.
        self.template_context_processors: dict[
            ft.AppOrBlueprintKey, list[ft.TemplateContextProcessorCallable]
        ] = defaultdict(list, {None: [_default_template_ctx_processor]})

        #: A data structure of functions to call to modify the keyword
        #: arguments passed to the view function, in the format
        #: ``{scope: [functions]}``. The ``scope`` key is the name of a
        #: blueprint the functions are active for, or ``None`` for all
        #: requests.
        #:
        #: To register a function, use the
        #: :meth:`url_value_preprocessor` decorator.
        #:
        #: This data structure is internal. It should not be modified
        #: directly and its format may change at any time.
        self.url_value_preprocessors: dict[
            ft.AppOrBlueprintKey,
            list[ft.URLValuePreprocessorCallable],
        ] = defaultdict(list)

        #: A data structure of functions to call to modify the keyword
        #: arguments when generating URLs, in the format
        #: ``{scope: [functions]}``. The ``scope`` key is the name of a
        #: blueprint the functions are active for, or ``None`` for all
        #: requests.
        #:
        #: To register a function, use the :meth:`url_defaults`
        #: decorator.
        #:
        #: This data structure is internal. It should not be modified
        #: directly and its format may change at any time.
        self.url_default_functions: dict[
            ft.AppOrBlueprintKey, list[ft.URLDefaultCallable]
        ] = defaultdict(list)

    def __repr__(self) -> str:
        return f"<{type(self).__name__} {self.name!r}>"

    def _check_setup_finished(self, f_name: str) -> None:
        raise NotImplementedError

    @property
    def static_folder(self) -> str | None:
        """The absolute path to the configured static folder. ``None``
        if no static folder is set.
        """
        if self._static_folder is not None:
            return os.path.join(self.root_path, self._static_folder)
        else:
            return None

    @static_folder.setter
    def static_folder(self, value: str | os.PathLike[str] | None) -> None:
        if value is not None:
            value = os.fspath(value).rstrip(r"\/")

        self._static_folder = value

    @property
    def has_static_folder(self) -> bool:
        """``True`` if :attr:`static_folder` is set.

        .. versionadded:: 0.5
        """
        return self.static_folder is not None

    @property
    def static_url_path(self) -> str | None:
        """The URL prefix that the static route will be accessible from.

        If it was not configured during init, it is derived from
        :attr:`static_folder`.
        """
        if self._static_url_path is not None:
            return self._static_url_path

        if self.static_folder is not None:
            basename = os.path.basename(self.static_folder)
            return f"/{basename}".rstrip("/")

        return None

    @static_url_path.setter
    def static_url_path(self, value: str | None) -> None:
        if value is not None:
            value = value.rstrip("/")

        self._static_url_path = value

    @cached_property
    def jinja_loader(self) -> BaseLoader | None:
        """The Jinja loader for this object's templates. By default this
        is a class :class:`jinja2.loaders.FileSystemLoader` to
        :attr:`template_folder` if it is set.

        .. versionadded:: 0.5
        """
        if self.template_folder is not None:
            return FileSystemLoader(os.path.join(self.root_path, self.template_folder))
        else:
            return None

    def _method_route(
        self,
        method: str,
        rule: str,
        options: dict[str, t.Any],
    ) -> t.Callable[[T_route], T_route]:
        if "methods" in options:
            raise TypeError("Use the 'route' decorator to use the 'methods' argument.")

        return self.route(rule, methods=[method], **options)

    @setupmethod
    def get(self, rule: str, **options: t.Any) -> t.Callable[[T_route], T_route]:
        """Shortcut for :meth:`route` with ``methods=["GET"]``.

        .. versionadded:: 2.0
        """
        return self._method_route("GET", rule, options)

    @setupmethod
    def post(self, rule: str, **options: t.Any) -> t.Callable[[T_route], T_route]:
        """Shortcut for :meth:`route` with ``methods=["POST"]``.

        .. versionadded:: 2.0
        """
        return self._method_route("POST", rule, options)

    @setupmethod
    def put(self, rule: str, **options: t.Any) -> t.Callable[[T_route], T_route]:
        """Shortcut for :meth:`route` with ``methods=["PUT"]``.

        .. versionadded:: 2.0
        """
        return self._method_route("PUT", rule, options)

    @setupmethod
    def delete(self, rule: str, **options: t.Any) -> t.Callable[[T_route], T_route]:
        """Shortcut for :meth:`route` with ``methods=["DELETE"]``.

        .. versionadded:: 2.0
        """
        return self._method_route("DELETE", rule, options)

    @setupmethod
    def patch(self, rule: str, **options: t.Any) -> t.Callable[[T_route], T_route]:
        """Shortcut for :meth:`route` with ``methods=["PATCH"]``.

        .. versionadded:: 2.0
        """
        return self._method_route("PATCH", rule, options)

    @setupmethod
    def route(self, rule: str, **options: t.Any) -> t.Callable[[T_route], T_route]:
        """Decorate a view function to register it with the given URL
        rule and options. Calls :meth:`add_url_rule`, which has more
        details about the implementation.

        .. code-block:: python

            @app.route("/")
            def index():
                return "Hello, World!"

        See :ref:`url-route-registrations`.

        The endpoint name for the route defaults to the name of the view
        function if the ``endpoint`` parameter isn't passed.

        The ``methods`` parameter defaults to ``["GET"]``. ``HEAD`` and
        ``OPTIONS`` are added automatically.

        :param rule: The URL rule string.
        :param options: Extra options passed to the
            :class:`~werkzeug.routing.Rule` object.
        """

        def decorator(f: T_route) -> T_route:
            endpoint = options.pop("endpoint", None)
            self.add_url_rule(rule, endpoint, f, **options)
            return f

        return decorator

    @setupmethod
    def add_url_rule(
        self,
        rule: str,
        endpoint: str | None = None,
        view_func: ft.RouteCallable | None = None,
        provide_automatic_options: bool | None = None,
        **options: t.Any,
    ) -> None:
        """Register a rule for routing incoming requests and building
        URLs. The :meth:`route` decorator is a shortcut to call this
        with the ``view_func`` argument. These are equivalent:

        .. code-block:: python

            @app.route("/")
            def index():
                ...

        .. code-block:: python

            def index():
                ...

            app.add_url_rule("/", view_func=index)

        See :ref:`url-route-registrations`.

        The endpoint name for the route defaults to the name of the view
        function if the ``endpoint`` parameter isn't passed. An error
        will be raised if a function has already been registered for the
        endpoint.

        The ``methods`` parameter defaults to ``["GET"]``. ``HEAD`` is
        always added automatically, and ``OPTIONS`` is added
        automatically by default.

        ``view_func`` does not necessarily need to be passed, but if the
        rule should participate in routing an endpoint name must be
        associated with a view function at some point with the
        :meth:`endpoint` decorator.

        .. code-block:: python

            app.add_url_rule("/", endpoint="index")

            @app.endpoint("index")
            def index():
                ...

        If ``view_func`` has a ``required_methods`` attribute, those
        methods are added to the passed and automatic methods. If it
        has a ``provide_automatic_methods`` attribute, it is used as the
        default if the parameter is not passed.

        :param rule: The URL rule string.
        :param endpoint: The endpoint name to associate with the rule
            and view function. Used when routing and building URLs.
            Defaults to ``view_func.__name__``.
        :param view_func: The view function to associate with the
            endpoint name.
        :param provide_automatic_options: Add the ``OPTIONS`` method and
            respond to ``OPTIONS`` requests automatically.
        :param options: Extra options passed to the
            :class:`~werkzeug.routing.Rule` object.
        """
        raise NotImplementedError

    @setupmethod
    def endpoint(self, endpoint: str) -> t.Callable[[F], F]:
        """Decorate a view function to register it for the given
        endpoint. Used if a rule is added without a ``view_func`` with
        :meth:`add_url_rule`.

        .. code-block:: python

            app.add_url_rule("/ex", endpoint="example")

            @app.endpoint("example")
            def example():
                ...

        :param endpoint: The endpoint name to associate with the view
            function.
        """

        def decorator(f: F) -> F:
            self.view_functions[endpoint] = f
            return f

        return decorator

    @setupmethod
    def before_request(self, f: T_before_request) -> T_before_request:
        """Register a function to run before each request.

        For example, this can be used to open a database connection, or
        to load the logged in user from the session.

        .. code-block:: python

            @app.before_request
            def load_user():
                if "user_id" in session:
                    g.user = db.session.get(session["user_id"])

        The function will be called without any arguments. If it returns
        a non-``None`` value, the value is handled as if it was the
        return value from the view, and further request handling is
        stopped.

        This is available on both app and blueprint objects. When used on an app, this
        executes before every request. When used on a blueprint, this executes before
        every request that the blueprint handles. To register with a blueprint and
        execute before every request, use :meth:`.Blueprint.before_app_request`.
        """
        self.before_request_funcs.setdefault(None, []).append(f)
        return f

    @setupmethod
    def after_request(self, f: T_after_request) -> T_after_request:
        """Register a function to run after each request to this object.

        The function is called with the response object, and must return
        a response object. This allows the functions to modify or
        replace the response before it is sent.

        If a function raises an exception, any remaining
        ``after_request`` functions will not be called. Therefore, this
        should not be used for actions that must execute, such as to
        close resources. Use :meth:`teardown_request` for that.

        This is available on both app and blueprint objects. When used on an app, this
        executes after every request. When used on a blueprint, this executes after
        every request that the blueprint handles. To register with a blueprint and
        execute after every request, use :meth:`.Blueprint.after_app_request`.
        """
        self.after_request_funcs.setdefault(None, []).append(f)
        return f

    @setupmethod
    def teardown_request(self, f: T_teardown) -> T_teardown:
        """Register a function to be called when the request context is
        popped. Typically this happens at the end of each request, but
        contexts may be pushed manually as well during testing.

        .. code-block:: python

            with app.test_request_context():
                ...

        When the ``with`` block exits (or ``ctx.pop()`` is called), the
        teardown functions are called just before the request context is
        made inactive.

        When a teardown function was called because of an unhandled
        exception it will be passed an error object. If an
        :meth:`errorhandler` is registered, it will handle the exception
        and the teardown will not receive it.

        Teardown functions must avoid raising exceptions. If they
        execute code that might fail they must surround that code with a
        ``try``/``except`` block and log any errors.

        The return values of teardown functions are ignored.

        This is available on both app and blueprint objects. When used on an app, this
        executes after every request. When used on a blueprint, this executes after
        every request that the blueprint handles. To register with a blueprint and
        execute after every request, use :meth:`.Blueprint.teardown_app_request`.
        """
        self.teardown_request_funcs.setdefault(None, []).append(f)
        return f

    @setupmethod
    def context_processor(
        self,
        f: T_template_context_processor,
    ) -> T_template_context_processor:
        """Registers a template context processor function. These functions run before
        rendering a template. The keys of the returned dict are added as variables
        available in the template.

        This is available on both app and blueprint objects. When used on an app, this
        is called for every rendered template. When used on a blueprint, this is called
        for templates rendered from the blueprint's views. To register with a blueprint
        and affect every template, use :meth:`.Blueprint.app_context_processor`.
        """
        self.template_context_processors[None].append(f)
        return f

    @setupmethod
    def url_value_preprocessor(
        self,
        f: T_url_value_preprocessor,
    ) -> T_url_value_preprocessor:
        """Register a URL value preprocessor function for all view
        functions in the application. These functions will be called before the
        :meth:`before_request` functions.

        The function can modify the values captured from the matched url before
        they are passed to the view. For example, this can be used to pop a
        common language code value and place it in ``g`` rather than pass it to
        every view.

        The function is passed the endpoint name and values dict. The return
        value is ignored.

        This is available on both app and blueprint objects. When used on an app, this
        is called for every request. When used on a blueprint, this is called for
        requests that the blueprint handles. To register with a blueprint and affect
        every request, use :meth:`.Blueprint.app_url_value_preprocessor`.
        """
        self.url_value_preprocessors[None].append(f)
        return f

    @setupmethod
    def url_defaults(self, f: T_url_defaults) -> T_url_defaults:
        """Callback function for URL defaults for all view functions of the
        application.  It's called with the endpoint and values and should
        update the values passed in place.

        This is available on both app and blueprint objects. When used on an app, this
        is called for every request. When used on a blueprint, this is called for
        requests that the blueprint handles. To register with a blueprint and affect
        every request, use :meth:`.Blueprint.app_url_defaults`.
        """
        self.url_default_functions[None].append(f)
        return f

    @setupmethod
    def errorhandler(
        self, code_or_exception: type[Exception] | int
    ) -> t.Callable[[T_error_handler], T_error_handler]:
        """Register a function to handle errors by code or exception class.

        A decorator that is used to register a function given an
        error code.  Example::

            @app.errorhandler(404)
            def page_not_found(error):
                return 'This page does not exist', 404

        You can also register handlers for arbitrary exceptions::

            @app.errorhandler(DatabaseError)
            def special_exception_handler(error):
                return 'Database connection failed', 500

        This is available on both app and blueprint objects. When used on an app, this
        can handle errors from every request. When used on a blueprint, this can handle
        errors from requests that the blueprint handles. To register with a blueprint
        and affect every request, use :meth:`.Blueprint.app_errorhandler`.

        .. versionadded:: 0.7
            Use :meth:`register_error_handler` instead of modifying
            :attr:`error_handler_spec` directly, for application wide error
            handlers.

        .. versionadded:: 0.7
           One can now additionally also register custom exception types
           that do not necessarily have to be a subclass of the
           :class:`~werkzeug.exceptions.HTTPException` class.

        :param code_or_exception: the code as integer for the handler, or
                                  an arbitrary exception
        """

        def decorator(f: T_error_handler) -> T_error_handler:
            self.register_error_handler(code_or_exception, f)
            return f

        return decorator

    @setupmethod
    def register_error_handler(
        self,
        code_or_exception: type[Exception] | int,
        f: ft.ErrorHandlerCallable,
    ) -> None:
        """Alternative error attach function to the :meth:`errorhandler`
        decorator that is more straightforward to use for non decorator
        usage.

        .. versionadded:: 0.7
        """
        exc_class, code = self._get_exc_class_and_code(code_or_exception)
        self.error_handler_spec[None][code][exc_class] = f

    @staticmethod
    def _get_exc_class_and_code(
        exc_class_or_code: type[Exception] | int,
    ) -> tuple[type[Exception], int | None]:
        """Get the exception class being handled. For HTTP status codes
        or ``HTTPException`` subclasses, return both the exception and
        status code.

        :param exc_class_or_code: Any exception class, or an HTTP status
            code as an integer.
        """
        exc_class: type[Exception]

        if isinstance(exc_class_or_code, int):
            try:
                exc_class = default_exceptions[exc_class_or_code]
            except KeyError:
                raise ValueError(
                    f"'{exc_class_or_code}' is not a recognized HTTP"
                    " error code. Use a subclass of HTTPException with"
                    " that code instead."
                ) from None
        else:
            exc_class = exc_class_or_code

        if isinstance(exc_class, Exception):
            raise TypeError(
                f"{exc_class!r} is an instance, not a class. Handlers"
                " can only be registered for Exception classes or HTTP"
                " error codes."
            )

        if not issubclass(exc_class, Exception):
            raise ValueError(
                f"'{exc_class.__name__}' is not a subclass of Exception."
                " Handlers can only be registered for Exception classes"
                " or HTTP error codes."
            )

        if issubclass(exc_class, HTTPException):
            return exc_class, exc_class.code
        else:
            return exc_class, None


def _endpoint_from_view_func(view_func: ft.RouteCallable) -> str:
    """Internal helper that returns the default endpoint for a given
    function.  This always is the function name.
    """
    assert view_func is not None, "expected view func if endpoint is not provided."
    return view_func.__name__


def _path_is_relative_to(path: pathlib.PurePath, base: str) -> bool:
    # Path.is_relative_to doesn't exist until Python 3.9
    try:
        path.relative_to(base)
        return True
    except ValueError:
        return False


def _find_package_path(import_name: str) -> str:
    """Find the path that contains the package or module."""
    root_mod_name, _, _ = import_name.partition(".")

    try:
        root_spec = importlib.util.find_spec(root_mod_name)

        if root_spec is None:
            raise ValueError("not found")
    except (ImportError, ValueError):
        # ImportError: the machinery told us it does not exist
        # ValueError:
        #    - the module name was invalid
        #    - the module name is __main__
        #    - we raised `ValueError` due to `root_spec` being `None`
        return os.getcwd()

    if root_spec.submodule_search_locations:
        if root_spec.origin is None or root_spec.origin == "namespace":
            # namespace package
            package_spec = importlib.util.find_spec(import_name)

            if package_spec is not None and package_spec.submodule_search_locations:
                # Pick the path in the namespace that contains the submodule.
                package_path = pathlib.Path(
                    os.path.commonpath(package_spec.submodule_search_locations)
                )
                search_location = next(
                    location
                    for location in root_spec.submodule_search_locations
                    if _path_is_relative_to(package_path, location)
                )
            else:
                # Pick the first path.
                search_location = root_spec.submodule_search_locations[0]

            return os.path.dirname(search_location)
        else:
            # package with __init__.py
            return os.path.dirname(os.path.dirname(root_spec.origin))
    else:
        # module
        return os.path.dirname(root_spec.origin)  # type: ignore[type-var, return-value]


def find_package(import_name: str) -> tuple[str | None, str]:
    """Find the prefix that a package is installed under, and the path
    that it would be imported from.

    The prefix is the directory containing the standard directory
    hierarchy (lib, bin, etc.). If the package is not installed to the
    system (:attr:`sys.prefix`) or a virtualenv (``site-packages``),
    ``None`` is returned.

    The path is the entry in :attr:`sys.path` that contains the package
    for import. If the package is not installed, it's assumed that the
    package was imported from the current working directory.
    """
    package_path = _find_package_path(import_name)
    py_prefix = os.path.abspath(sys.prefix)

    # installed to the system
    if _path_is_relative_to(pathlib.PurePath(package_path), py_prefix):
        return py_prefix, package_path

    site_parent, site_folder = os.path.split(package_path)

    # installed to a virtualenv
    if site_folder.lower() == "site-packages":
        parent, folder = os.path.split(site_parent)

        # Windows (prefix/lib/site-packages)
        if folder.lower() == "lib":
            return parent, package_path

        # Unix (prefix/lib/pythonX.Y/site-packages)
        if os.path.basename(parent).lower() == "lib":
            return os.path.dirname(parent), package_path

        # something else (prefix/site-packages)
        return site_parent, package_path

    # not installed
    return None, package_path


Filepath: githubCode\tests\typing\typing_app_decorators.py:

from __future__ import annotations

from flask import Flask
from flask import Response

app = Flask(__name__)


@app.after_request
def after_sync(response: Response) -> Response:
    return Response()


@app.after_request
async def after_async(response: Response) -> Response:
    return Response()


@app.before_request
def before_sync() -> None:
    ...


@app.before_request
async def before_async() -> None:
    ...


@app.teardown_appcontext
def teardown_sync(exc: BaseException | None) -> None:
    ...


@app.teardown_appcontext
async def teardown_async(exc: BaseException | None) -> None:
    ...


Filepath: githubCode\tests\typing\typing_error_handler.py:

from __future__ import annotations

from http import HTTPStatus

from werkzeug.exceptions import BadRequest
from werkzeug.exceptions import NotFound

from flask import Flask

app = Flask(__name__)


@app.errorhandler(400)
@app.errorhandler(HTTPStatus.BAD_REQUEST)
@app.errorhandler(BadRequest)
def handle_400(e: BadRequest) -> str:
    return ""


@app.errorhandler(ValueError)
def handle_custom(e: ValueError) -> str:
    return ""


@app.errorhandler(ValueError)
def handle_accept_base(e: Exception) -> str:
    return ""


@app.errorhandler(BadRequest)
@app.errorhandler(404)
def handle_multiple(e: BadRequest | NotFound) -> str:
    return ""


Filepath: githubCode\tests\typing\typing_route.py:

from __future__ import annotations

import typing as t
from http import HTTPStatus

from flask import Flask
from flask import jsonify
from flask import stream_template
from flask.templating import render_template
from flask.views import View
from flask.wrappers import Response

app = Flask(__name__)


@app.route("/str")
def hello_str() -> str:
    return "<p>Hello, World!</p>"


@app.route("/bytes")
def hello_bytes() -> bytes:
    return b"<p>Hello, World!</p>"


@app.route("/json")
def hello_json() -> Response:
    return jsonify("Hello, World!")


@app.route("/json/dict")
def hello_json_dict() -> dict[str, t.Any]:
    return {"response": "Hello, World!"}


@app.route("/json/dict")
def hello_json_list() -> list[t.Any]:
    return [{"message": "Hello"}, {"message": "World"}]


class StatusJSON(t.TypedDict):
    status: str


@app.route("/typed-dict")
def typed_dict() -> StatusJSON:
    return {"status": "ok"}


@app.route("/generator")
def hello_generator() -> t.Generator[str, None, None]:
    def show() -> t.Generator[str, None, None]:
        for x in range(100):
            yield f"data:{x}\n\n"

    return show()


@app.route("/generator-expression")
def hello_generator_expression() -> t.Iterator[bytes]:
    return (f"data:{x}\n\n".encode() for x in range(100))


@app.route("/iterator")
def hello_iterator() -> t.Iterator[str]:
    return iter([f"data:{x}\n\n" for x in range(100)])


@app.route("/status")
@app.route("/status/<int:code>")
def tuple_status(code: int = 200) -> tuple[str, int]:
    return "hello", code


@app.route("/status-enum")
def tuple_status_enum() -> tuple[str, int]:
    return "hello", HTTPStatus.OK


@app.route("/headers")
def tuple_headers() -> tuple[str, dict[str, str]]:
    return "Hello, World!", {"Content-Type": "text/plain"}


@app.route("/template")
@app.route("/template/<name>")
def return_template(name: str | None = None) -> str:
    return render_template("index.html", name=name)


@app.route("/template")
def return_template_stream() -> t.Iterator[str]:
    return stream_template("index.html", name="Hello")


@app.route("/async")
async def async_route() -> str:
    return "Hello"


class RenderTemplateView(View):
    def __init__(self: RenderTemplateView, template_name: str) -> None:
        self.template_name = template_name

    def dispatch_request(self: RenderTemplateView) -> str:
        return render_template(self.template_name)


app.add_url_rule(
    "/about",
    view_func=RenderTemplateView.as_view("about_page", template_name="about.html"),
)


Filepath: githubCode\tests\test_apps\blueprintapp\__init__.py:

from flask import Flask

app = Flask(__name__)
app.config["DEBUG"] = True
from blueprintapp.apps.admin import admin  # noqa: E402
from blueprintapp.apps.frontend import frontend  # noqa: E402

app.register_blueprint(admin)
app.register_blueprint(frontend)


Filepath: githubCode\tests\test_apps\cliapp\app.py:

from flask import Flask

testapp = Flask("testapp")


Filepath: githubCode\tests\test_apps\cliapp\factory.py:

from flask import Flask


def create_app():
    return Flask("app")


def create_app2(foo, bar):
    return Flask("_".join(["app2", foo, bar]))


def no_app():
    pass


Filepath: githubCode\tests\test_apps\cliapp\importerrorapp.py:

from flask import Flask

raise ImportError()

testapp = Flask("testapp")


Filepath: githubCode\tests\test_apps\cliapp\multiapp.py:

from flask import Flask

app1 = Flask("app1")
app2 = Flask("app2")


Filepath: githubCode\tests\test_apps\cliapp\__init__.py:



Filepath: githubCode\tests\test_apps\helloworld\hello.py:

from flask import Flask

app = Flask(__name__)


@app.route("/")
def hello():
    return "Hello World!"


Filepath: githubCode\tests\test_apps\helloworld\wsgi.py:

from hello import app  # noqa: F401


Filepath: githubCode\tests\test_apps\subdomaintestmodule\__init__.py:

from flask import Module

mod = Module(__name__, "foo", subdomain="foo")


Filepath: githubCode\tests\test_apps\blueprintapp\apps\__init__.py:



Filepath: githubCode\tests\test_apps\blueprintapp\apps\admin\__init__.py:

from flask import Blueprint
from flask import render_template

admin = Blueprint(
    "admin",
    __name__,
    url_prefix="/admin",
    template_folder="templates",
    static_folder="static",
)


@admin.route("/")
def index():
    return render_template("admin/index.html")


@admin.route("/index2")
def index2():
    return render_template("./admin/index.html")


Filepath: githubCode\tests\test_apps\blueprintapp\apps\frontend\__init__.py:

from flask import Blueprint
from flask import render_template

frontend = Blueprint("frontend", __name__, template_folder="templates")


@frontend.route("/")
def index():
    return render_template("frontend/index.html")


@frontend.route("/missing")
def missing_template():
    return render_template("missing_template.html")


Filepath: githubCode\tests\test_apps\cliapp\inner1\__init__.py:

from flask import Flask

application = Flask(__name__)


Filepath: githubCode\tests\test_apps\cliapp\inner1\inner2\flask.py:

from flask import Flask

app = Flask(__name__)


Filepath: githubCode\tests\test_apps\cliapp\inner1\inner2\__init__.py:



Filepath: Code\app.py:

print("Hello world!")