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

You can mock a django signal by mocking the ModelSignal class at django.db.models.signals.py like this:

@patch("django.db.models.signals.ModelSignal.send")
def test_overwhelming(self, mocker_signal):
    obj = Object()

That should do the trick. Note that this will mock ALL signals no matter which object you are using.

If by any chance you use the mocker library instead, it can be done like this:

from mocker import Mocker, ARGS, KWARGS

def test_overwhelming(self):
    mocker = Mocker()
    # mock the post save signal
    msave = mocker.replace("django.db.models.signals")
    msave.post_save.send(KWARGS)
    mocker.count(0, None)

    with mocker:
        obj = Object()

It's more lines but it works pretty well too :)