Repository: psf/black
File: fuzz.py (Python)

Code before:
        line_length=st.just(88) | st.integers(0, 200),
        string_normalization=st.booleans(),
        is_pyi=st.booleans(),
    ),
)
def test_idempotent_any_syntatically_valid_python(
    src_contents: str, mode: black.FileMode
) -> None:
    # Before starting, let's confirm that the input string is valid Python:
    compile(src_contents, "<string>", "exec")  # else the bug is in hypothesmith

    # Then format the code...
    try:
        dst_contents = black.format_str(src_contents, mode=mode)
    except black.InvalidInput:
        # This is a bug - if it's valid Python code, as above, Black should be
        # able to cope with it.  See issues #970, #1012, #1358, and #1557.
        # TODO: remove this try-except block when issues are resolved.
        return
    except TokenError as e:
        # The Python3.7 'compile' method accepts input that terminates with a
        # multi-line continuation character (\), but black rejects it.
        # TODO: remove this special-case once py37 reaches end-of-life
        exception_message = e.args[0]
        if (
            src_contents.endswith("\\")
            and exception_message == "EOF in multi-line statement"
        ):
            return

    # And check that we got equivalent and stable output.
    black.assert_equivalent(src_contents, dst_contents)
    black.assert_stable(src_contents, dst_contents, mode=mode)

    # Future test: check that pure-python and mypyc versions of black
    # give identical output for identical input?


if __name__ == "__main__":
    # Run tests, including shrinking and reporting any known failures.
    test_idempotent_any_syntatically_valid_python()

    # If Atheris is available, run coverage-guided fuzzing.
    # (if you want only bounded fuzzing, just use `pytest fuzz.py`)
    try:
        import sys
        import atheris
    except ImportError:
        pass
    else:
        test = test_idempotent_any_syntatically_valid_python

Review comment (bug):
I don't think this condition (`endswith.("\\")`) is perfect.

This build would have still failed with that condition in place: https://github.com/psf/black/runs/1904676745

Code after:
    mode=st.builds(
        black.FileMode,
        line_length=st.just(88) | st.integers(0, 200),
        string_normalization=st.booleans(),
        is_pyi=st.booleans(),
    ),
)
def test_idempotent_any_syntatically_valid_python(
    src_contents: str, mode: black.FileMode
) -> None:
    # Before starting, let's confirm that the input string is valid Python:
    compile(src_contents, "<string>", "exec")  # else the bug is in hypothesmith

    # Then format the code...
    try:
        dst_contents = black.format_str(src_contents, mode=mode)
    except black.InvalidInput:
        # This is a bug - if it's valid Python code, as above, Black should be
        # able to cope with it.  See issues #970, #1012, #1358, and #1557.
        # TODO: remove this try-except block when issues are resolved.
        return
    except TokenError as e:
        if (
            e.args[0] == "EOF in multi-line statement"
            and re.search(r"\r?\n\\\r?\n", src_contents) is not None
        ):
            # This is a bug - if it's valid Python code, as above, Black should be
            # able to cope with it.  See issue #1012.
            # TODO: remove this block when the issue is resolved.
            return
        raise

    # And check that we got equivalent and stable output.
    black.assert_equivalent(src_contents, dst_contents)
    black.assert_stable(src_contents, dst_contents, mode=mode)

    # Future test: check that pure-python and mypyc versions of black
    # give identical output for identical input?


if __name__ == "__main__":
    # Run tests, including shrinking and reporting any known failures.
    test_idempotent_any_syntatically_valid_python()

    # If Atheris is available, run coverage-guided fuzzing.
    # (if you want only bounded fuzzing, just use `pytest fuzz.py`)
    try:
        import sys
        import atheris
    except ImportError:
        pass