def METHOD_NAME(self, mocker: MockerFixture, tmp_path: Path) -> None:
    """Test __init__."""
    gitignore_filter = mocker.patch("igittigitt.IgnoreParser", Mock())
    gitignore_filter.return_value = gitignore_filter
    obj = SourceCode(tmp_path)
    assert obj._include_files_in_hash == []
    assert obj.gitignore_filter == gitignore_filter
    gitignore_filter.assert_called_once_with()
    assert obj.project_root == tmp_path
    assert obj.root_directory == tmp_path
    gitignore_filter.parse_rule_files.assert_called_once_with(tmp_path)
    gitignore_filter.add_rule.assert_has_calls(
        [call(".git/", tmp_path), call(".gitignore", tmp_path)]
    )