How do I mock a django signal handler?

Question

I have a signal_handler connected through a decorator, something like this very simple one:

@receiver(post_save, sender=User, 
          dispatch_uid=\'myfil         


        

Answer 1

In django 1.9 you can mock all receivers with something like this

# replace actual receivers with mocks
mocked_receivers = []
for i, receiver in enumerate(your_signal.receivers):
    mock_receiver = Mock()
    your_signal.receivers[i] = (receiver[0], mock_receiver)
    mocked_receivers.append(mock_receiver)

...  # whatever your test does

# ensure that mocked receivers have been called as expected
for mocked_receiver in mocked_receivers:
    assert mocked_receiver.call_count == 1
    mocked_receiver.assert_called_with(*your_args, sender="your_sender", signal=your_signal, **your_kwargs)

This replaces all receivers with mocks, eg ones you've registered, ones pluggable apps have registered and ones that django itself has registered. Don't be suprised if you use this on post_save and things start breaking.

You may want to inspect the receiver to determine if you actually want to mock it.