def slug_provider(max_length):
    """
    Provides the tested slug data

    :param max_length: maximum number of characters in the slug
    :return: list of tuples where the first tuple element is string value and the second tuple element is
        whether such a value is valid
    """
    return [
        ("", False),
        ("a", True),
        ("a" * max_length, True),
        ("a" * (max_length+1), False),
        ("ivanov", True),
        ("IVANOV", True),
        ("Ivanov", True),
        ("iVaNoV", True),
        ("ivanov123", True),
        ("ivanov-ivan", True),
        ("ivanov_ivan", True),
        ("ivanov.ivan", False),
        ("ivanov,ivan", False),
        ("(ivanov-ivan)", False),
        ("иванов-иван", False),
    ]