flask 单元测试拆解期间的错误/异常

Question

我正在尝试对 flask 应用程序调用的一些方法进行单元测试。 这些方法与 flask 响应 object 交互，我试图模拟它以进行测试（我不想测试 flask 响应，它工作得很好。）当我尝试运行我的测试时，测试按预期运行但他们在拆解期间抛出异常。

示例代码

def my_func():
    key = do_some_stuff()
    if key:
        return Response("key", status=200)
    else:
        return Response("key", status=500)

来自 conftest.py 的夹具代码

@pytest.fixture()
def request_context():
    app = create_app()
    return app.test_request_context()

测试代码

def test_get_my_stuff(mocker, request_context):
    def mock_Response_get(*args, **kwargs):
        class mockResponse:
            def __init__(self, status):
                self.status_code = kwargs["status"]

            def __call__(self, *args, **kwargs):
                return self.status_code

        resp = mockResponse(kwargs["status"])
        return resp


    with request_context:
        mocker.patch("my_func.Response", side_effect=mock_Response_get)
        response = my_modules.get_identity()
        assert response.status_code == 500

结果

python -m pytest

pytestconfig = <_pytest.config.Config object at 0x7fa1025054c0>

    def _mocker(pytestconfig: Any) -> Generator[MockerFixture, None, None]:
        """
        Return an object that has the same interface to the `mock` module, but
        takes care of automatically undoing all patches after each test method.
        """
        result = MockerFixture(pytestconfig)
        yield result
>       result.stopall()

/usr/local/lib/python3.9/site-packages/pytest_mock/plugin.py:425: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
/usr/local/lib/python3.9/site-packages/pytest_mock/plugin.py:99: in stopall
    p.stop()
/usr/local/lib/python3.9/unittest/mock.py:1553: in stop
    return self.__exit__(None, None, None)
/usr/local/lib/python3.9/unittest/mock.py:1522: in __exit__
    delattr(self.target, self.attribute)
/usr/local/lib/python3.9/site-packages/werkzeug/local.py:316: in __get__
    obj = instance._get_current_object()  # type: ignore[misc]
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

    def _get_current_object() -> T:
        try:
            obj = local.get()  # type: ignore[union-attr]
        except LookupError:
>           raise RuntimeError(unbound_message) from None
E           RuntimeError: Working outside of request context.
E           
E           This typically means that you attempted to use functionality that needed
E           an active HTTP request. Consult the documentation on testing for
E           information about how to avoid this problem.

/usr/local/lib/python3.9/site-packages/werkzeug/local.py:513: RuntimeError

据我所知，在 with request_context 块内部运行应该确保不会出现“在请求上下文之外工作”错误。

我在这里做错了什么愚蠢的事吗？

Answer 1

使用flask 2.2.2、pytest 7.2.0和pytest-mock 3.7.0 ，我无法重现您的问题。 也就是说， mocker fixture 的result.stopall()在测试 function 结束后会被调用，这也意味着在测试请求上下文退出后。 您可以尝试以下...

1. 让你的 fixture 创建请求上下文并且不yield任何结果； yield意味着您的 fixture 也会进行拆卸，其中它只会退出上下文：

@pytest.fixture()
def request_context():
    with create_app().test_request_context():
        yield

2. 更改调用（和拆除）fixture 的顺序，将 fixture 放在mocker之前。 另外，不要在测试中创建另一个测试请求上下文，因为它已经存在：

def test_get_my_stuff(request_context, mocker):
    def mock_Response_get(*args, **kwargs):
        class mockResponse:
            def __init__(self, status):
                self.status_code = kwargs["status"]

            def __call__(self, *args, **kwargs):
                return self.status_code

        resp = mockResponse(kwargs["status"])
        return resp

    mocker.patch("tests.app.Response", side_effect=mock_Response_get)
    response = my_func()
    assert response.status_code == 500