[Python] Trouble Adding Mocks and Patches to a Test on a Route

I have a Flask API with a route like:

from flask import current_app
from utils.linked_list_handler import get_ll
import json

@detail_bp.route("/get_base_details", methods=["GET"])
def get_all_base_details():
"""Get the details of all nodes with the q_type 'base'"""
ll = get_ll(current_app)
base_list=ll.getByQType("base")
return json.dumps(base_list)


that I am trying to test. In order to do so, I want to patch get_ll() and mock ll and ll.getByQType(). I tried to do this like:

class TestGetBaseDetails:
def test_get_some_base_details(self, test_client: FlaskClient, mocker):
"""
GIVEN a Flask app configured for testing
WHEN the '/get_base_details' route is requested with the
'GET' method while there is a linked list with at least
one Node with a Question with a q_type of "base"
THEN check that the response shows the q_detail of those
base questions
"""
# mock get_ll
mock_get_ll = mocker.patch("backend.routes.blueprints.details.get_ll")
# mock a ll
mock_ll = mocker.Mock()
mock_ll.getByQType.return_value = ["q_detail_1", "q_detail_2"]
# mock the assignment
mock_get_ll.return_value = mock_ll

response = test_client.get("/get_base_details")
assert response.status_code == 200
assert json.loads(response.data) == ["q_detail_1", "q_detail_2"]

mock_get_ll.assert_called_once()
mock_ll.assert_called_once()


However, this tests fails with the following message: FAILED backend/tests/test_details.py::TestGetBaseDetails::test_get_some_base_details - AssertionError: assert [] == ['q_detail_1', 'q_detail_2']

An empty list is the return value the route gives when the search doesn't match anything. Checking the two assert_called_once() methods, it shows that neither are ever called. I assume that this is all due to some error within my implementation of the patch and mocks, but I don't know what specifically went wrong or how to check for it.

Any advice would be greatly appreciated. Thank you in advance.

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