我如何模拟芹菜任务的类方法

Question

Using python 2.7, celery 3.0.24 and mock 1.0.1. I have this:

class FancyTask(celery.Task):
    @classmethod
    def helper_method1(cls, name):
        """do some remote request depending on name"""
        return 'foo' + name + 'bar'

    def __call__(self, *args, **kwargs):
        funcname = self.name.split()[-1]
        bigname = self.helper_method1(funcname)
        return bigname


@celery.task(base=FancyTask)
def task1(*args, **kwargs):
    pass

@celery.task(base=FancyTask)
def task2(*args, **kwargs):
    pass

how can I patch helper_method1 while testing either task?

I've tried something like:

 import mock
 from mymodule import tasks

 class TestTasks(unittest.TestCase):
     def test_task1(self):
         task = tasks.task1
         task.helper_method1 = mock.MagickMock(return_value='42')
         res = task.delay('blah')
         task.helper_method1.assert_called_with('blah')

and the test is failing. The original function is the one being called. And no, this question didn't help me.

Answer 1

(I don't have a celery instance up and running so it's difficult for me to test this)

The target function in your application code is a classmethod. The function your test code is mocking is an instance method.

Does changing the test_task1 like this help -

 def test_task1(self):
     FancyTask.helper_method1 = mock.MagickMock(return_value='42') 
     task = tasks.task1
     res = task.delay('blah')
     task.helper_method1.assert_called_with('blah')

You probably also need to change the assert_called_with so it is called from the class level instead of the instance level.

change

     task.helper_method1.assert_called_with('blah')    

to

     FancyTask.helper_method1.assert_called_with('blah')