如何写django中form的测试用例

可简可繁，

可插库，可字符，

要测试valid，也要测试invalid，

可用csrf，也可用context。

放一个全面的，

实践中，找一个最优的组合就好。

class NewTopicTests(TestCase):
    def setUp(self):
        self.board = Board.objects.create(name='Django', description='Django borad.')
        self.user = User.objects.create_user(username=')

    def test_csrf(self):
        url = reverse('new_topic', kwargs={'pk': 1})
        response = self.client.get(url)
        self.assertContains(response, 'csrfmiddlewaretoken')

    def test_contains_form(self):
        url = reverse('new_topic', kwargs={'pk': 1})
        response = self.client.post(url, {})
        form = response.context.get('form')
        self.assertIsInstance(form, NewTopicForm)

    def test_valid_form(self):
        topic = Topic.objects.create(
            subject='foo',
            board=self.board,
            starter=self.user
        )
        post = Post.objects.create(
            message='bar',
            topic=topic,
            created_by=self.user
        )
        data = {
            # 'subject': topic.subject,
            # 'message': post.message,
            'subject': 'foo',
            'message': 'bar',
        }
        form = NewTopicForm(data=data)
        self.assertTrue(form.is_valid())

    def test_invalid_form(self):
        topic = Topic.objects.create(
            subject='foo',
            board=self.board,
            starter=self.user
        )
        post = Post.objects.create(
            message='',
            topic=topic,
            created_by=self.user
        )
        data = {
            'subject': topic.subject,
            'message': post.message,
        }
        form = NewTopicForm(data=data)
        self.assertFalse(form.is_valid())

    def test_new_topic_valid_post_data(self):
        url = reverse('new_topic', kwargs={'pk': 1})
        data = {
            'subject': 'Test title',
            'message': 'Lorem ipsum dolor sit amet'
        }

        response = self.client.post(url, data)
        self.assertTrue(Topic.objects.exists())
        self.assertTrue(Post.objects.exists())

    def test_new_topic_invalid_post_data(self):
        url = reverse('new_topic', kwargs={'pk': 1})
        response = self.client.post(url, {})
        form = response.context.get('form')
        self.assertTrue(form.errors)
        self.assertEqual(response.status_code, 200)

    def test_new_topic_invalid_post_data_empty_fields(self):
        url = reverse('new_topic', kwargs={'pk': 1})
        data = {
            'subject': '',
            'message': ''
        }

        response = self.client.post(url, data)
        self.assertEqual(response.status_code, 200)
        self.assertFalse(Topic.objects.exists())
        self.assertFalse(Post.objects.exists())