带有@patch decorator的模拟类属性

如何使用 @patch 装潢师?

进行以下测试:

def test_hangup(self):
    stub_call = Mock()

    cut = TelefonyInterface()
    cut.call = stub_call
    cut.hangup()

    self.assertEqual(1, stub_call.hangup.call_count)
    self.assertEqual(None, cut.call)

我想用 mock.patch 这里的装饰使它更容易阅读。像这样的:

@patch.object(TelefonyInterface, 'call')
def test_hangup(self, call):
    cut = TelefonyInterface()
    cut.hangup()

    self.assertEqual(1, call.hangup.call_count)
    self.assertEqual(None, cut.call)

但我得到了以下属性错误:

AttributeError: <class '(...).TelefonyInterface'> does not have the attribute 'call'

我的电话接口是这样的:

class TelefonyInterface:
    def __init__(self):
        self.call = None

    def dial(self, number):
        self.call = ...

    def hangup(self):
        if self.call:
            self.call.hangup()

    ...

正确的方法是什么?