def test_empty_removes_all_entities(repo: Repository) -> None:
"""
Given: A full repository
When: calling empty
Then: No entity remains in the repository
"""
books = BookFactory.batch(25)
genres = GenreFactory.batch(20)
repo.add(books)
repo.add(genres)
repo.commit()
result = repo.empty()
assert result is None
assert repo.all(Book) == []
assert repo.all(Genre) == []
def get_books() -> List[Book]:
"""Return some books."""
return BookFactory.batch(5)