def test_repository_returns_date_of_next_movie(session_factory):
    repo = SqlAlchemyRepository(session_factory)

    movie = repo.get_movie(3)
    next_date = repo.get_year_of_next_movie(movie)

    assert next_date == 2016
def test_repository_returns_none_when_there_are_no_subsequent_movies(
        session_factory):
    repo = SqlAlchemyRepository(session_factory)

    movie = repo.get_movie(10)
    next_date = repo.get_year_of_next_movie(movie)

    assert next_date is None