Want to disable signals in Django testing

Question

So I have various signals and handlers which are sent across apps. However, when I perform tests / go into 'testing mode', I want these handlers to be disabled.

Is there a Django-specific way of disabling signals/handlers when in testing mode? I can think of a very simple way (of including the handlers within an if TESTING clause) but I was wondering if there was a better way built into Django?...

Answer 1

I found this question when looking to disable a signal for a set of test cases and Germano's answer lead me to the solution but it takes the opposite approach so I thought I'd add it.

In your test class:

class MyTest(TestCase):     def setUp(self):         # do some setup         signals.disconnect(listener, sender=FooModel) 

Instead of adding decision code to adding the signal I instead disabled it at the point of testing which feels like a nicer solution to me (as the tests should be written around the code rather than the code around the tests). Hopefully is useful to someone in the same boat!

Edit: Since writing this I've been introduced to another way of disabling signals for testing. This requires the factory_boy package (v2.4.0+) which is very useful for simplifying tests in Django. You're spoilt for choice really:

import factory from django.db.models import signals  class MyTest(TestCase):     @factory.django.mute_signals(signals.pre_save, signals.post_save)     def test_something(self): 

Caveat thanks to ups: it mutes signals inside factory and when an object is created, but not further inside test when you want to make explicit save() - signal will be unmuted there. If this is an issue then using the simple disconnect in setUp is probably the way to go.

Answer 2

Here's a full example with imports on how to disable a specific signal in a test, if you don't want to use FactoryBoy.

from django.db.models import signals from myapp.models import MyModel  class MyTest(TestCase):      def test_no_signal(self):         signals.post_save.disconnect(sender=MyModel, dispatch_uid="my_id")          ... after this point, the signal is disabled ... 

This should be matched against your receiver, this example would match this receiver:

@receiver(post_save, sender=MyModel, dispatch_uid="my_id") 

I tried to disable the signal without specifying the dispatch_uid and it didn't work.