使用模拟补丁来模拟实例方法

Question

我在使用富有想象力的名称“模拟测试库”测试 Django 应用程序时尝试模拟某些内容。我似乎无法完全让它工作，我正在尝试这样做：

models.py

from somelib import FooClass

class Promotion(models.Model):
    foo = models.ForeignKey(FooClass)
    def bar(self):
       print "Do something I don't want!"


test.py

class ViewsDoSomething(TestCase):
    view = 'my_app.views.do_something'

    def test_enter_promotion(self):
        @patch.object(my_app.models.FooClass, 'bar')
        def fake_bar(self, mock_my_method):
            print "Do something I want!"
            return True

        self.client.get(reverse(view))

我做错了什么？

Answer 1

patch.object()

指定第三个参数允许指定模拟对象/方法。否则，将使用默认的

MagicMock

对象。

    def fake_bar(self):
        print "Do something I want!"
        return True

    @patch.object(my_app.models.FooClass, 'bar', fake_bar)
    def test_enter_promotion(self):
        self.client.get(reverse(view))
        # Do something I want!

请注意，如果您将模拟对象指定为第三个参数，则默认的

MagicMock()

是

不再

传递到修补的对象中——例如不再： def test_enter_promotion(self, mock_method):

而是：

def test_enter_promotion(self):

https://docs.python.org/3/library/unittest.mock.html#patch-object

Answer 2

class ViewsDoSomething(TestCase):
    view = 'my_app.views.do_something'

    @patch.object(my_app.models.FooClass, 'bar')
    def test_enter_promotion(self, mock_method):
        self.client.get(reverse(view))

Answer 3

assert_called

等操作，请使用

patch.object

并将替换方法包装在

MagicMock(side_effect=)中，即：

with patch.object(class_to_mock, attribute_name, \
 MagicMock(side_effect=replacement_method)) as replacement_method_mock:

例如：

from unittest.mock import patch, MagicMock

def fake_bar(self):
    print "Do something I want!"
    return True

def test_enter_promotion(self):
    with patch.object(my_app.models.FooClass, 'bar', MagicMock(side_effect=fake_bar)) as fake_bar_mock:
        self.client.get(reverse(view))
        # Do something I want!
        fake_bar_mock.assert_called()