Function test_samefile_false_negatives

testing/test_pathlib.py:433–449

import_file() should not raise ImportPathMismatchError if the paths are exactly equal on Windows. It seems directories mounted as UNC paths make os.path.samefile return False, even when they are clearly equal.

(tmp_path: Path, monkeypatch: MonkeyPatch)

@pytest.mark.skipif(not sys.platform.startswith("win"), reason="Windows only")
def test_samefile_false_negatives(tmp_path: Path, monkeypatch: MonkeyPatch) -> None:
    """
    import_file() should not raise ImportPathMismatchError if the paths are exactly
    equal on Windows. It seems directories mounted as UNC paths make os.path.samefile
    return False, even when they are clearly equal.
    """
    module_path = tmp_path.joinpath("my_module.py")
    module_path.write_text("def foo(): return 42")
    monkeypatch.syspath_prepend(tmp_path)

    with monkeypatch.context() as mp:
        # Forcibly make os.path.samefile() return False here to ensure we are comparing
        # the paths too. Using a context to narrow the patch as much as possible given
        # this is an important system function.
        mp.setattr(os.path, "samefile", lambda x, y: False)
        module = import_path(module_path, root=tmp_path)
    assert getattr(module, "foo")() == 42


class TestImportLibMode: