def test_tmp_path_factory_fixes_up_world_readable_permissions(
    tmp_path: Path, monkeypatch: MonkeyPatch
) -> None:
    """Verify that if a /tmp/pytest-of-foo directory already exists with
    world-readable permissions, it is fixed.

    pytest used to mkdir with such permissions, that's why we fix it up.
    """
    # Use the test's tmp_path as the system temproot (/tmp).
    monkeypatch.setenv("PYTEST_DEBUG_TEMPROOT", str(tmp_path))
    tmp_factory = TempPathFactory(None, 3, "all", lambda *args: None, _ispytest=True)
    basetemp = tmp_factory.getbasetemp()

    # Before - simulate bad perms.
    os.chmod(basetemp.parent, 0o777)
    assert (basetemp.parent.stat().st_mode & 0o077) != 0

    tmp_factory = TempPathFactory(None, 3, "all", lambda *args: None, _ispytest=True)
    basetemp = tmp_factory.getbasetemp()

    # After - fixed.
    assert (basetemp.parent.stat().st_mode & 0o077) == 0
Verify that if a /tmp/pytest-of-foo directory already exists with
    world-readable permissions, it is fixed.

    pytest used to mkdir with such permissions, that's why we fix it up.
    
testing/test_tmpdir.py