在Django 2中模拟RelatedManager [英] Mocking a RelatedManager in Django 2

问题描述

此问题直接与此问题，但现在看来那已经过时了.

This question is directly related to this question, but that one is now outdated it seems.

我正在尝试测试视图而不必访问数据库.为此，我需要在用户上模拟RelatedManager.

I am trying to test a view without having to access the database. To do that I need to Mock a RelatedManager on the user.

我正在使用pytest和pytest-mock.

models.py

models.py

# truncated for brevity, taken from django-rest-knox
class AuthToken(models.Model):
    user = models.ForeignKey(
        User, 
        null=False, 
        blank=False,
        related_name='auth_token_set', 
        on_delete=models.CASCADE
    )

views.py

class ChangeEmail(APIView):
    permission_classes = [permissions.IsAdmin]
    serializer_class = serializers.ChangeEmail

    def post(self, request, *args, **kwargs):
        serializer = self.get_serializer(data=request.data)
        serializer.is_valid(raise_exception=True)

        user = request.user
        user.email = request.validated_data['email']
        user.save()

        # Logout user from all devices
        user.auth_token_set.all().delete() # <--- How do I mock this?

        return Response(status=status.HTTP_200_OK)

test_views.py

test_views.py

def test_valid(mocker, user_factory):
    user = user_factory.build()
    user.id = 1

    data = {
        'email': '[e-mail]'
    }

    factory = APIRequestFactory()
    request = factory.post('/', data=data)
    force_authenticate(request, user)

    mocker.patch.object(user, "save")

    related_manager = mocker.patch(
        'django.db.models.fields.related.ReverseManyToOneDescriptor.__set__',
        return_vaue=mocker.MagicMock()
    )
    related_manager.all = mocker.MagicMock()
    related_manager.all.delete = mocker.MagicMock()

    response = ChangeEmail.as_view()(request)
    assert response.status_code == status.HTTP_200_OK

从链接的问题的答案中提取了我试图修补的ReverseManyToOneDescriptor.但是，它似乎并未真正受到嘲笑，因为在尝试删除用户的auth_token_set时，测试仍在尝试连接数据库.

Drawing from the answer in the linked question I tried to patch the ReverseManyToOneDescriptor. However, it does not appear to actually get mocked because the test is still trying to connect to the database when it tries to delete the user's auth_token_set.

推荐答案

您将需要模拟create_reverse_many_to_one_manager工厂函数的返回值.示例:

You'll need to mock the return value of the create_reverse_many_to_one_manager factory function. Example:

def test_valid(mocker):
    mgr = mocker.MagicMock()
    mocker.patch(
        'django.db.models.fields.related_descriptors.create_reverse_many_to_one_manager', 
        return_value=mgr
    )

    user = user_factory.build()
    user.id = 1
    ...
    mgr.assert_called()

请注意，上面的示例将模拟所有模型的转速管理器.如果您需要更细粒度的方法(例如，仅修补程序User.auth_token的转速管理器，其余未修补)，请提供自定义的工厂实现，例如

Beware that the above example will mock the rev manager for all models. If you need a more fine-grained approach (e.g. patch User.auth_token's rev manager only, leave the rest unpatched), provide a custom factory impl, e.g.

def test_valid(mocker):
    mgr = mocker.MagicMock()
    factory_orig = related_descriptors.create_reverse_many_to_one_manager
    def my_factory(superclass, rel):
        if rel.model == User and rel.name == 'auth_token_set':
            return mgr
        else:
            return factory_orig(superclass, rel)

    mocker.patch(
        'django.db.models.fields.related_descriptors.create_reverse_many_to_one_manager',
        my_factory
    )

    user = user_factory.build()
    user.id = 1
    ...
    mgr.assert_called()

这篇关于在Django 2中模拟RelatedManager的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！