Pedro Müller

Passionate about clean code, modern web technologies and ai

less than 1 minute read

Celery Task Testing

Goal: Test task logic without a real broker and without flakiness.

  • CELERY_ALWAYS_EAGER = True (in test settings): tasks run inline when you call .delay(). No worker needed. Use with CELERY_EAGER_PROPAGATES_EXCEPTIONS = True so exceptions surface.
  • Mock external deps: API calls, email, storage — patch them so tests don’t hit the network and are deterministic.
  • Unit test the task: call my_task.delay(args) then result.get() and assert on return value and side effects (e.g. DB state).
  • Test failures too: mock that raises, assert task fails or retries as expected.
  • Chains/groups: use .apply() in tests to run synchronously and assert on the result.

Pattern: Set EAGER in setUp or test settings, patch myapp.tasks.external_api (or wherever the task imports it from), then run the task and assert. Keep tests fast and isolated.