Package: pyrsatest
Pyramid SQLAlchemy unit testing utilitiesA package which provides Python classes that enables SQLAlchemy functionality to be
mocked in unit tests for an application written in Pyramid or a similar framework.These utilities are designed to help in writing unit tests for situations
where test setup is overly time-consuming or otherwise problematic.
This may include the requirement for extensive amounts of request data for which
queries filter upon, or for an extensive variety of related records
to be created due to complex database schemas etc.In mocking and explicitly setting return
values for SQLAlchemy queries, the appreciation of
control flow is made easier in many cases. Note that in using the provided objects,
such as mocking SQLAlchemy ORM queries throughMockDbSession,
whether queries are written correctly or return results are as expected
is left untested.The source for this project is availablehere.Available functionality and example usageMockModelUseful for representing objects such as ORM query results.
Desired attributes are set in their construction from keywords arguments.>>> from pyrasatest import MockModel
>>> mm = MockModel(name='Paul', age='34')
>>> print(f'My name is {mm.name} and my age is {mm.age}')
My name is Paul and my age is 34For testing code which accesses an SQLAlchemy query result object using indexing
as an alternative to dotted attribute lookup (i.e.namedtuple-like access),
values will be returned according to ordering of kwargs which are passed to the constructor, for example:>>> mock_model = MockModel(foo='0', bar='1')
>>> mock_model[0]
'0'For Python versions before 3.6, where dictionaries have no ordering, the following
method should be used to specify return values from indexing:>>> mock_model.set_result_items(['foo_value', 'bar_value'])
>>> mock_model[0]
'foo_value'LazyAttrMockModelis similar toMockModelexcept that in the case of a
failed attribute lookup, it will returnNoneinstead of raisingAttributeError.MockRequestMockRequestobjects, which inherit fromPyramid.testing.DummyRequest,
have an instance ofMockDbSessionas an attribute.
Database interactions, which would usually involve an SQLAlchemy session instance
throughrequest.dbsession, will use an instance ofMockDbSessioninstead.
This can be customized accordingly, usage is demonstrated below.MockDbSessionTo set query results more generally, seeMockQueryusage notes.
Query results can be set in a specific manner,
according to the model or model property which
is the first positional argument passed todbession.queryin the unit of code
being tested. The following view callable has multipledbession.querycalls:class ExampleView:
    def __init__(self, request):
        self.request = request

    @view_config(route_name='order_info', renderer='../templates/mytemplate.mako')
    def get_order_info(self):
        try:
            order = self.request.dbsession.query(models.Order).filter(
                models.Order.id == self.request.params.get('order_id')).one()
            a = type(order)
        except exc.SQLAlchemyError:
            return {'status': 'order not found'}

        try:
            product_id = self.request.dbsession.query(models.Product.id).filter(
                models.Product.number == self.request.params.get('product_number')).one()[0]
        except exc.SQLAlchemyError:
            return {'status': f'product not found for order id {order.id}'}

        try:
            acc_name = self.request.dbsession.query(models.Account.name).filter(
                models.Account.id == self.request.params.get('account_id')).one()[0]
        except exc.SQLAlchemyError:
            return {'status': f'account not found for order id {order.id}'}

        return {
            'status': 'ok',
            'order_number': order.number,
            'product_id': product_id,
            'account_name': acc_name,
        }The following tests for the above demonstrates the setting of return values
for specific queries:...
from pyrasatest import MockModel, MockRequest
from sqlalchemy import exc

from app.models import Account, Order, Product
from app.views.default import ExampleView

class ExampleViewTestCase(unittest.TestCase):
    def setUp(self):
        self.view = ExampleView(MockRequest())

    def test_get_order_info_order_not_found(self):
        self.view.request.dbsession.query_return_values = {
            Order: exc.SQLAlchemyError
        }
        self.assertEqual(
            {'status': 'order not found'},
            self.view.get_order_info()
        )

    def test_get_order_info_product_not_found(self):
        mock_order = MockModel(id=12)
        self.view.request.dbsession.query_return_values = {
            # MockQuery can be used as a value, this allows customization
            # Order: MockQuery(one_=mock_order) 
            Order: mock_order,
            Product.id: exc.SQLAlchemyError
        }
        self.assertEqual(
            {'status': f'product not found for order id {mock_order.id}'},
            self.view.get_order_info()
        )

    def test_get_order_info_account_not_found(self):
        mock_order = MockModel(id=12)
        self.view.request.dbsession.query_return_values = {
            Order: mock_order,
            Product.id: MockModel(id=25),
            Account.name: exc.SQLAlchemyError
        }
        self.assertEqual(
            {'status': f'account not found for order id {mock_order.id}'},
            self.view.get_order_info()
        )

    def test_get_order_info(self):
        mock_order = MockModel(id=12, number=5)
        mock_product = MockModel(id=25)
        mock_account = MockModel(name='test_acc')
        query_return_values = {
            Order: mock_order,
            Product.id: mock_product,
            Account.name: mock_account
        }
        self.view.request.dbsession.query_return_values = query_return_values
        expected_output = {
            'status': 'ok',
            'order_number': mock_order.number,
            'product_id': mock_product[0],
            'account_name': mock_account[0],
        }
        self.assertEqual(expected_output, self.view.get_order_info())PartialMockDbSessionSubclassesMockDbSessionand makes it so ORM query mocking is restricted to
only the specified queries. In creating an instance,
a test database session instance must be provided,
as well as adictwhose data specifies which queries
to mock along with desired return values.If adbsession.querycall contains no key matching the first positional
argument passed to it, then that call will not be mocked.
Otherwise it is used as the return value from any
chained.one(),.first()or.all()calls,
or anExceptionraised if the value is anExceptionclass.In the following example, suppose a unit of code being tested contained the
followingdbsession.querycalls:accounts = request.dbsession.query(Account).filter(...).one()
supplier = request.dbsession.query(Supplier, Country.id).filter(...).one()
products = request.dbsession.query(Product.id).filter(...).all()Then to selectively mock the last two calls (and leave the first one unmocked),PartialMockDbSessioncan be used as follows:...
from pyramid.testing import DummyRequest
from pyrasatest import PartialMockDbSession
from sqlalchemy import exc

from app.models import Account, Supplier, Product
from app.models.meta import Base
from app.views import ExampleView

class ExampleViewTestCase(unittest.TestCase):
    @classmethod
    def setUpClass(cls):
        engine = create_engine('sqlite:///:memory:')
        cls.session = scoped_session(sessionmaker(bind=engine))
        Base.metadata.create_all(engine)
        request = DummyRequest()
        request.dbsession = cls.session
        cls.view = ExampleView(request)
        acc1 = Account(name='acc1', number='123')
        ...


    def test_get_account_and_product_number_with_mocked_product_query(self):
        self.view.request.params = {'account_id': self.accounts[0].id}
        mock_product = MockModel(number=32)
        self.view.request.dbsession = PartialMockDbSession(
            query_return_values={Product.id: mock_product},
            dbsession=self.session
        )
        acc_name = self.accounts[0].name
        self.assertEqual(
            {'account_name': acc_name, 'product_number': mock_product[0]},
            self.view.get_account_and_product_number()
        )MockQueryAs defined inMockQuery.__init__, a number of keywords arguments have meaning
which affect behavior on subsequent method calls.To set returns values for queries which end in.first()and.one()as in the
following view callable:class ExampleView:
    def __init__(self, request):
        self.request = request

    @view_config(route_name='account_info', renderer=template_path)
    def get_account_info(self):
        account = self.request.dbsession.query(models.Account).filter(
            models.Account.id == self.request.params.get('account_id')
        ).first()
        if not account:
            try:
                account = self.request.dbsession.query(models.Account).filter(
                    models.Account.name == 'guest'
                ).one()
            except exc.SQLAlchemyError:
                return {}
        return {'account_name': account.name, 'account_number': account.number}InstantiateMockQuerywith the appropriate keyword arguments and assign toself.request.dbsessionas in the following example. Usage also involves testing of a condition whereexc.SQLAlchemyis raised:from pyrasatest import MockModel, MockQuery
from sqlalchemy import exc

from app.views.default import ExampleView

class ExampleViewTestCase(unittest.TestCase):
    def setUp(self):
        self.view = ExampleView(MockRequest()) 

    def test_get_account_info(self):
        mock_acc = MockModel(name='Abc', number='123')
        self.view.request.dbsession.return_value = MockQuery(first_=mock_acc)
        self.assertEqual(
            {'account_name': mock_acc.name, 'account_number': mock_acc.number},
            self.view.get_account_info()
        )

    def test_get_account_info_account_not_found(self):
        self.view.request.dbsession.return_value = MockQuery(
            first_=None,
            raise_exc=exc.SQLAlchemyError
        )
        self.assertEqual({}, self.view.get_account_info())For query results returned by.all(), where the code being tested iterates
over the result, pass in the desired return value in a manner similar to:MockQuery(all_=['result1', 'result2'])InstallationTo install the package you can use pip:$ pip install pyrasatest