Python mock, django and requests

问题:

So, I've just started using mock with a Django project. I'm trying to mock out part of a view which makes a request to a remote API to confirm a subscription request was genuine (a form of verification as per the spec I'm working to).

What I have resembles:

class SubscriptionView(View):
    def post(self, request, **kwargs):
        remote_url = request.POST.get('remote_url')
        if remote_url:
            response = requests.get(remote_url, params={'verify': 'hello'})

        if response.status_code != 200:
            return HttpResponse('Verification of request failed')

What I now want to do is to use mock to mock out the requests.get call to change the response, but I can't work out how to do this for the patch decorator. I'd thought you do something like:

@patch(requests.get)
def test_response_verify(self):
    # make a call to the view using self.app.post (WebTest), 
    # requests.get makes a suitable fake response from the mock object

How do I achieve this?

回答1:

You're almost there. You're just calling it slightly incorrectly.

from mock import call, patch


@patch('my_app.views.requests')
def test_response_verify(self, mock_requests):
    # We setup the mock, this may look like magic but it works, return_value is
    # a special attribute on a mock, it is what is returned when it is called
    # So this is saying we want the return value of requests.get to have an
    # status code attribute of 200
    mock_requests.get.return_value.status_code = 200

    # Here we make the call to the view
    response = SubscriptionView().post(request, {'remote_url': 'some_url'})

    self.assertEqual(
        mock_requests.get.call_args_list,
        [call('some_url', params={'verify': 'hello'})]
    )

You can also test that the response is the correct type and has the right content.

回答2:

It's all in the documentation:

patch(target, new=DEFAULT, spec=None, create=False, spec_set=None, autospec=None, new_callable=None, **kwargs)

target should be a string in the form ‘package.module.ClassName’.

from mock import patch

# or @patch('requests.get')
@patch.object(requests, 'get')
def test_response_verify(self):
    # make a call to the view using self.app.post (WebTest), 
    # requests.get makes a suitable fake response from the mock object