def test_cannot_save_empty_book_details(self):
list_of_books = ListfOfBooks.objects.create()
book = Book()
book.title = "" # empty book detail (title)
book.current_page = 6
book.total_pages = 344
book.list_of_books = list_of_books
with self.assertRaises(ValidationError):
book.save()
book.full_clean() # fully checks empty value in TextField.
