Snippet

Signal Disconnector Test Utility for Asserting Muted Handlers

Testing Django signals often requires isolating side effects. Inheriting from `ContextDecorator` allows this helper to function seamlessly both as a context manager (`with MuteSignal(...):`) and as a test function decorator (`@MuteSignal(...)`).

snippet.py

python

from contextlib import ContextDecorator
from django.db.models.signals import ModelSignal
 
class MuteSignal(ContextDecorator):
    def __init__(self, signal: ModelSignal, receiver):
        self.signal = signal
        self.receiver = receiver
 
    def __enter__(self):
        self.signal.disconnect(self.receiver)
        return self
 
    def __exit__(self, exc_type, exc_val, exc_tb):
        self.signal.connect(self.receiver)
        return False

django

Breakdown

class MuteSignal(ContextDecorator):

Extends standard library ContextDecorator to enable dual context manager and decorator capabilities.

def __init__(self, signal: ModelSignal, receiver):

Accepts the target Django signal instance and receiver callback function to manipulate.

def __enter__(self):

Context entry hook that unbinds the receiver from listening to signal dispatches.

self.signal.disconnect(self.receiver)

Detaches the receiver handler from the signal registry during block execution.

def __exit__(self, exc_type, exc_val, exc_tb):

Context exit hook re-attaching signal handler regardless of exceptions inside the block.

self.signal.connect(self.receiver)

Restores original signal connection state upon block termination.

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Signal Disconnector Test Utility for Asserting Muted Handlers

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