python – 测试类方法中的pytest monkeypatch.setattr()

我有一个测试类,测试方法很少,我想从测试方法中修补一些应用程序类和方法.
在pytest docs中,我找到了an example如何使用monkeypatch模块进行测试.例如,所有测试都只是函数,而不是测试类方法.

但我有一个测试方法类：

class MyTest(TestCase):
   def setUp():
     pass

   def test_classmethod(self, monkeypatch):
     # here I want to use monkeypatch.setattr()
     pass

只是通过monkeypatch作为方法参数显然是行不通的.所以看起来像py.test魔法不能这样工作.

所以问题很简单,也许是愚蠢的：如何在测试类方法中使用monkeypatch.setattr()进行pytest？

解决方法:

它以这种形式can’t work

While pytest supports receiving fixtures via test function arguments
for non-unittest test methods, unittest.TestCase methods cannot
directly receive fixture function arguments as implementing that is
likely to inflict on the ability to run general unittest.TestCase test
suites.

您可以直接创建monkeypatch

from _pytest.monkeypatch import MonkeyPatch

class MyTest(TestCase):
   def setUp():
     self.monkeypatch = MonkeyPatch()

   def test_classmethod(self):
     self.monkeypatch.setattr ...
     ...

或者创建自己的fixture,它会将monkeypatch添加到你的类中,并使用@ pytest.mark.usefixtures

@pytest.fixture(scope="class")
def monkeypatch_for_class(request):
    request.cls.monkeypatch = MonkeyPatch()

@pytest.mark.usefixtures("monkeypatch_for_class")
class MyTest(TestCase):
   def setUp():
     pass

   def test_classmethod(self):
     self.monkeypatch.setattr ...
     ...