def test_repository_can_retrieve_movie():
    mem_repo = MemoryRepository()
    movie = Movie("Up", 2009, 1)
    mem_repo.add_movie(movie)
    got_movie = mem_repo.get_movie(1)

    assert got_movie == movie
def test_repository_does_not_retrieve_a_non_existent_movie():
    mem_repo = MemoryRepository()
    movie = Movie("Up", 2009, 1)
    mem_repo.add_movie(movie)
    got_movie = mem_repo.get_movie(7)

    assert got_movie is None
def test_repository_can_add_movie():
    mem_repo = MemoryRepository()
    movie = Movie("Up", 2009, 1)
    mem_repo.add_movie(movie)

    assert mem_repo.get_movie(1) is movie