Mock cookies attribute of requests.session

Question

Session.cookies is defined inside the Session constructor and thus I can't mock it. Is there any way to mock it?

from requests import Session
from settings import URL
from unittest.mock import patch

@patch.object(Session, 'cookies', new='my custom mock object')
def test_request():
    assert function_that_uses_request_cookies()

This raises AttributeError: <class 'requests.sessions.Session'> does not have the attribute 'cookies'

If session instance was defined on the module scope, I could patch the session instance directly. But session is defined only on function_that_uses_request_cookies scope. Is there any way to patch the instance inside the function scope?

Answer 1

As written, the code will patch an attribute of the Session class, but what you want to do is patch an attribute of a Session instance. To do this without interrupting other aspects of session behaviour, you can create a mock object that wraps Session .

def test_request():
    mock_session_klass = MagicMock(wraps=Session)
    with patch('requests.Session', new=mock_session_klass):
        session_instance = mock_session_klass.return_value
        session_instance.cookies.return_value = 'my custom mock object'
        assert function_that_uses_request_cookies()