python - 如何模拟 django 信号处理程序？

Question

我有一个通过装饰器连接的 signal_handler，就像这个非常简单的:

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

我想做的是用模拟库 http://www.voidspace.org.uk/python/mock/ 模拟它 在测试中，检查 django 调用它的次数。我现在的代码是这样的:

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)

这里的问题是即使模拟了原始信号处理程序也会被调用，很可能是因为 @receiver 装饰器在某处存储了信号处理程序的副本，所以我模拟了错误的代码.

所以问题是:我如何模拟我的信号处理程序以使我的测试工作？

请注意，如果我将信号处理程序更改为:

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)

我改为模拟 _support_function，一切都按预期工作。

Answer 1

可能更好的主意是模拟信号处理程序内部的功能，而不是处理程序本身。使用 OP 的代码:

@receiver(post_save, sender=User, dispatch_uid='myfile.signal_handler_post_save_user')
def signal_handler_post_save_user(sender, *args, **kwargs):
  do_stuff()  # <-- mock this

def do_stuff():
   ... do stuff in here

然后模拟do_stuff:

with mock.patch('myapp.myfile.do_stuff') as mocked_handler:
    self.assert_equal(mocked_handler.call_count, 1)