def _helper_assert_file_contents(
    file_infos,
    target_contents,
    get_contents_mock,
):
    """
    Helper method to assert things about the get_contents_from_files method.
    Does not actually hit the disk.

    file_infos: array of { path, contents } dicts representing files. Array so
        that we can assert proper order calling
    target_contents: the final combined contents that should be returned by the
        get_contents_from_files method.
    """

    # This method will be used by the mock framework to return the right file
    # contents based on the file name.
    def return_file_contents(*args, **kwargs):
        for file_info in file_infos:
            if file_info['path'] == args[0]:
                return file_info['contents']
        raise TypeError('did not find path in test obj')

    get_contents_mock.side_effect = return_file_contents

    paths = [el['path'] for el in file_infos]
    actual = util.get_contents_from_files(*paths)
    assert actual == target_contents

    Helper method to assert things about the get_contents_from_files method.
    Does not actually hit the disk.

    file_infos: array of { path, contents } dicts representing files. Array so
        that we can assert proper order calling
    target_contents: the final combined contents that should be returned by the
        get_contents_from_files method.
    
test/util_test.py