Python 模拟补丁检查父类方法调用

我想对这个类方法进行单元测试

update

class EmployeeUpdateSerializer(serializers.ModelSerializer):

    def update(self, instance, data):
        shift_types = data.pop('shift_types', None)
        instance = super().update(instance, data)
        self.update_shift_type(instance, shift_types)
        return instance

我正在这样做

class TestEmployeeUpdateSerializer(TestCase):
    def setUp(self):
        self.company, self.user, self.header = create_user_session()
        self.serializer = EmployeeUpdateSerializer()

    def test_update(self):
        employee = self.user

        with patch.object(self.serializer, 'update') as update:
            with patch.object(self.serializer, 'update_shift_type') as update_shift_type:
                res = self.serializer.update(employee, dict())

                update.assert_called_once_with(employee, dict())
                update_shift_type.assert_called_once_with(employee, None)

                self.assertEqual(res, employee)

但这给了我一个错误

    Traceback (most recent call last):
  File "/Users/shahzadfarukh/my-croft/backend/account/tests/test_employee_serializers.py", line 222, in test_update
    update_shift_type.assert_called_once_with(employee, None)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/unittest/mock.py", line 830, in assert_called_once_with
    raise AssertionError(msg)
AssertionError: Expected 'update_shift_type' to be called once. Called 0 times.

---

请帮帮我！我做错了什么吗？

您已经模拟了

更新，所以它的原始代码不会被调用。如果要测试
update
调用的内容，必须调用原始版本，并且只模拟更新中调用的函数/方法。假设基类是像导入序列化程序那样导入的，您可以这样做（未测试）

您已经模拟了
update
，因此不会调用它的原始代码。如果你想测试
update
调用的内容，你必须调用原始版本，并且只模拟
update
@mrbeanbreman中调用的函数/方法。你能帮我举个例子吗？
class TestEmployeeUpdateSerializer(TestCase):
    def setUp(self):
        self.company, self.user, self.header = create_user_session()
        self.serializer = EmployeeUpdateSerializer()

     @patch('serializers.ModelSerializer.update')
     @patch('serializers.ModelSerializer.update_shift_type')
     def test_update(self, mocked_update_shift_type, mocked_update):
         employee = self.user
         res = self.serializer.update(employee, dict())
         mocked_update.assert_called_once_with(employee, dict())
         mocked_update_shift_type.assert_called_once_with(employee, None)
         self.assertEqual(res, employee)