def does_diff_include_ts_files(diff_files):
    """Returns true if diff includes TypeScript files.

    Args:
        diff_files: list(str). List of files changed.

    Returns:
        bool. Whether the diff contains changes in any TypeScript files.
    """

    for file_path in diff_files:
        if file_path.endswith(b'.ts'):
            return True
    return False