def test_get_alias_file_path(mock_join):
    """
    _get_alias_file_path should just join the example dir and the alias file
    name, to make sure we look in the right place for the file.
    """
    config_obj = _create_config(
        examples_dir='handy/dandy/examples/dir',
    )

    join_result = 'joined path'
    mock_join.return_value = join_result

    actual = util._get_alias_file_path(config_obj)
    assert actual == join_result
    mock_join.assert_called_once_with(
        config_obj.examples_dir,
        util.ALIAS_FILE_NAME
    )

    _get_alias_file_path should just join the example dir and the alias file
    name, to make sure we look in the right place for the file.
    
test/util_test.py