問題描述

我有一個通過裝飾器連接的 signal_handler，就像這個非常簡單的:

I have a signal_handler connected through a decorator, something like this very simple one:

@receiver(post_save, sender=User, 
          dispatch_uid='myfile.signal_handler_post_save_user')
def signal_handler_post_save_user(sender, *args, **kwargs):
   # do stuff

我想做的是用模擬庫 http://www.voidspace 模擬它.org.uk/python/mock/ 在測試中，檢查 django 調(diào)用它的次數(shù).我現(xiàn)在的代碼是這樣的:

What I want to do is to mock it with the mock library http://www.voidspace.org.uk/python/mock/ in a test, to check how many times django calls it. My code at the moment is something like:

def test_cache():
    with mock.patch('myapp.myfile.signal_handler_post_save_user') as mocked_handler:
        # do stuff that will call the post_save of User
    self.assert_equal(mocked_handler.call_count, 1)

這里的問題是即使模擬了原始信號處理程序也會被調(diào)用，很可能是因為 @receiver 裝飾器在某處存儲了信號處理程序的副本，所以我模擬了錯誤的代碼.

The problem here is that the original signal handler is called even if mocked, most likely because the @receiver decorator is storing a copy of the signal handler somewhere, so I'm mocking the wrong code.

所以問題是:我如何模擬我的信號處理程序以使我的測試工作?

So the question: how do I mock my signal handler to make my test work?

請注意，如果我將信號處理程序更改為:

Note that if I change my signal handler to:

def _support_function(*args, **kwargs):
    # do stuff

@receiver(post_save, sender=User, 
          dispatch_uid='myfile.signal_handler_post_save_user')
def signal_handler_post_save_user(sender, *args, **kwargs):
   _support_function(*args, **kwargs)

我改為模擬 _support_function，一切都按預(yù)期工作.

and I mock _support_function instead, everything works as expected.

推薦答案

所以，我最終得到了一種解決方案:模擬信號處理程序只是意味著將模擬本身連接到信號，所以這正是我做了:

So, I ended up with a kind-of solution: mocking a signal handler simply means to connect the mock itself to the signal, so this exactly is what I did:

def test_cache():
    with mock.patch('myapp.myfile.signal_handler_post_save_user', autospec=True) as mocked_handler:
        post_save.connect(mocked_handler, sender=User, dispatch_uid='test_cache_mocked_handler')
        # do stuff that will call the post_save of User
    self.assertEquals(mocked_handler.call_count, 1)  # standard django
    # self.assert_equal(mocked_handler.call_count, 1)  # when using django-nose

請注意，mock.patch 中的 autospec=True 是必需的，以使 post_save.connect 能夠在 上正確工作MagicMock，否則django會拋出一些異常，連接會失敗.

Notice that autospec=True in mock.patch is required in order to make post_save.connect to correctly work on a MagicMock, otherwise django will raise some exceptions and the connection will fail.

這篇關(guān)于如何模擬 django 信號處理程序?的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網(wǎng)！