How do I mock a django signal handler?

Possibly a better idea is to mock out the functionality inside the signal handler rather than the handler itself. Using the OP's code:

@receiver(post_save, sender=User, dispatch_uid='myfile.signal_handler_post_save_user')def signal_handler_post_save_user(sender, *args, **kwargs):  do_stuff()  # <-- mock thisdef do_stuff():   ... do stuff in here

Then mock do_stuff:

with mock.patch('myapp.myfile.do_stuff') as mocked_handler:    self.assert_equal(mocked_handler.call_count, 1)

So, I ended up with a kind-of solution: mocking a signal handler simply means to connect the mock itself to the signal, so this exactly is what I did:

def test_cache():    with mock.patch('myapp.myfile.signal_handler_post_save_user', autospec=True) as mocked_handler:        post_save.connect(mocked_handler, sender=User, dispatch_uid='test_cache_mocked_handler')        # do stuff that will call the post_save of User    self.assertEquals(mocked_handler.call_count, 1)  # standard django    # self.assert_equal(mocked_handler.call_count, 1)  # when using django-nose

Notice that autospec=True in mock.patch is required in order to make post_save.connect to correctly work on a MagicMock, otherwise django will raise some exceptions and the connection will fail.

take a look at mock_django . It has support for signals

https://github.com/dcramer/mock-django/blob/master/tests/mock_django/signals/tests.py