How to mock django's Q object

test_django_q.py

    @patch('quote_options.models.LiabilityLimit.objects.filter')
    @patch('quote.models.Q')
    def should_filter_with_q_object_in_get_liability_limits(self, q_object, limit_filter):
        manager_instance = Mock(spec=quote_models.LiabilityManager())
        policy = mock.Mock()

        q_instance = mock.Mock()
        q_or_method = mock.Mock()
        q_or_method.return_value = q_instance
        q_instance.__or__ = q_or_method
        q_object.return_value = q_instance

        results = quote_models.LiabilityManager.get_liability_limits(manager_instance, policy)

        limit_filter.assert_called_once_with(q_instance)
        self.assertEqual(2, q_or_method.call_count)
        self.assertEqual(limit_filter.return_value, results)

This seems like a very useful snippet for testing-out custom manager methods that call filter with Q objects, but I just can't seem to get it working in a small project of my own.

On what would be the line 13 in my project (it's not the same code, of course), I keep getting something similar to:

  File "/home/branko/.virtualenvs/conntrackt/local/lib/python2.7/site-packages/django/db/models/query_utils.py", line 44, in __init__
    super(Q, self).__init__(children=list(args) + list(six.iteritems(kwargs)))
TypeError: must be type, not MagicMock

Have you faced something like this before? I can post the full code sample from test (didn't want to spam your gist, so that's why I haven't :)

Ok, so in the end I figured out I was patching the object using a wrong namespace. Essentially, I failed to read:

http://www.voidspace.org.uk/python/mock/patch.html#where-to-patch

Thanks for the gist once again :)