Question

Question

I have a function that calls a url and then modifies that url’s response. How can I write a unit test for the portion of that function’s code that modifies the response, without having to rely on that url?

Example

my_module.py

import requests

def get_some_resource():
    url = 'http://httpbin.org/get'
    r = requests.get(url)
    # Special manipulation of returned text (what I want to test) simple example used
    output = r.text.upper()
    return output

What I’ve tried so far

• Using mock’s MagicMock() (you can’t use it to override a function’s variables, as far as I can tell)
• I’ve considered breaking apart the two sections of that function (the retrieval of the url and the modify of the response), however, I’m not clear if that’s necessary
• So much googling my hands hurt

Answer 1

If this is a unit test, you would just probably want to mock out the requests library. You can either just patch the whole thing, or just get, it doesn’t really matter.

It’d look like:

get = mock.Mock()
text = get.return_value.text = "hey I got this")
with mock.patch("my_module.requests.get", get):
    resource = get_some_resource()
self.assertEqual(resource, text.upper())

Cheers.