def test_book_autodelete(self): note1 = Note(text='text') note1.save() note2 = Note(text='text') note2.save() book = Book(title='title') book.save() book.notes.add(*[note1, note2]) note1.delete() self.assertTrue(Book.objects.all()) note2.delete() self.assertFalse(Book.objects.all())