Pythonmonkeypatch.setattr() 在模块范围内带有 pytest 固定装置

Question

首先，我的项目目录的相关部分如下所示：

└── my_package

    ├── my_subpackage

    │   ├── my_module.py

    |   └── other_module.py

    └── tests

        └── my_subpackage

            └── unit_test.py

我正在编写一些测试unit_test.py，需要在模块级别模拟外部资源。我想使用pytest fixture模块级范围并pytest monkeypatch完成此操作。这是我尝试过的片段unit_test.py：

import unittest.mock as mock

import pytest

from my_package.my_subpackage.my_module import MyClass

@pytest.fixture(scope='function')

def external_access(monkeypatch):

    external_access = mock.MagicMock()

    external_access.get_something = mock.MagicMock(

        return_value='Mock was used.')

    monkeypatch.setattr(

        'my_package.my_subpackage.my_module.ExternalAccess.get_something',

        external_access.get_something)

def test_get_something(external_access):

    instance = MyClass()

    instance.get_something()

    assert instance.data == 'Mock was used.'

一切正常。但是当我尝试将第 8 行从 更改@pytest.fixture(scope='function')为 时@pytest.fixture(scope='module')，出现以下错误。

ScopeMismatch: You tried to access the 'function' scoped fixture 'monkeypatch' with a 'module' scoped request object, involved factories

my_package\tests\unit_test.py:7:  def external_access(monkeypatch)

..\..\Anaconda3\envs\py37\lib\site-packages\_pytest\monkeypatch.py:20:  def monkeypatch()

有谁知道如何使用模块级范围进行monkeypatch？

如果有人想知道，这也是这两个模块的样子。

my_module.py

from my_package.my_subpackage.other_module import ExternalAccess

class MyClass(object):

    def __init__(self):

        self.external_access = ExternalAccess()

        self.data = None

    def get_something(self):

        self.data = self.external_access.get_something()

other_module.py

class ExternalAccess(object):

    def get_something(self):

        return 'Call to external resource.'