How to unit test code that runs celery tasks?

问题

The app I am working on is heavily asynchronous. The web application runs a lot of tasks through celery depending on user actions. The celery tasks themselves are capable of launching further tasks.

Code such as the one shown below occurs in our code base quite frequently.

def do_sth():
    logic();
    if condition:
         function1.apply_async(*args)
    else:
         function2.apply_asynch(*args)

Now we want to start unit testing any new code that we write and we are not sure how to do this. What we would like to assert in our pytest unit tests is that we want to see if function1 actually got called. We do not want to necessarily run function1 itself as we will have a unit test for the function1.

I do not want to be running celery as a process, neither do I want to run any AMQP broker during the unit test session.

Is this achievable?

Edit

It was pointed out that this is a duplicate of How do you unit test a Celery task?

It is not. Think about it. What I am asking is how to test if function has called function1 through apply_async. That question is about how do I test function1 itself. There is a major difference. I did hit that question before framing this one.

回答1:

Have a look at the Mock library which allows to replace functions you don't want to be invoked with "mocks" which look sufficiently similar to the original functions to convince the calling code that it's invoking the "real thing". You can then check that the mock was actually invoked and with what parameters. Example:

import mock

def test_do_sth():
    with mock.patch('function1.apply_async') as function1_mock:
        do_sth()
        assert function1_mock.called

来源：https://stackoverflow.com/questions/31739246/how-to-unit-test-code-that-runs-celery-tasks

标签

python

unit-testing

celery

pyramid

pytest