how can i monkeypatch request from starlette

[rajshahdev]

i want to mock monkeypatch the request library from starlette
and here I am using pytest

from starlette.requests import Request

@pytest.fixture
def user_1(monkeypatch, request: Request):
    monkeypatch.setattr(request,'scope', {"aws.event": {"requestContext":{"authorizer":{"claims":{"sub":"11bdd74a-90a1-455e-a2a8-64a0cad728ea","cognito:groups":"users"}}}}})
    # monkeypatch.setattr("app.utils.verify_sub_group.requester_group", "users")

but I got an error saying

value = '{"aws.event": {"requestContext":{"authorizer":{"claims":{"sub":"11bdd74a-90a1-455e-a2a8-64a0cad728ea","cognito:groups":"users"}}}}}'

or even when i pass in the test function

from starlette.requests import Request

def test_get_area_returns_area_of_feature(client, user_1, monkeypatch):
    monkeypatch.setattr("app.utils.verify_sub_group.requester_sub","11bdd74a-90a1-455e-a2a8-64a0cad728ea")
    monkeypatch.setattr("app.utils.verify_sub_group.requester_group","users")

it points to the original(actual) function

so how can I monkeypatch with request.scope from starlette

this is the function that I need to mock

def verify_sub_group(sub: UUID, request: Request):
    """this function returns true if the group and uuid match with cognito uuid."""

    requester_sub = request.scope['aws.event']['requestContext']['authorizer']['claims']['sub']
    requester_group = request.scope['aws.event']['requestContext']['authorizer']['claims']['cognito:groups']

[rajshahdev]

i want to mock monkeypatch the request library from starlette and here I am using pytest

from starlette.requests import Request

@pytest.fixture
def user_1(monkeypatch, request: Request):
    monkeypatch.setattr(request,'scope', {"aws.event": {"requestContext":{"authorizer":{"claims":{"sub":"11bdd74a-90a1-455e-a2a8-64a0cad728ea","cognito:groups":"users"}}}}})
    # monkeypatch.setattr("app.utils.verify_sub_group.requester_group", "users")

but I got an error saying

value = '{"aws.event": {"requestContext":{"authorizer":{"claims":{"sub":"11bdd74a-90a1-455e-a2a8-64a0cad728ea","cognito:groups":"users"}}}}}'

or even when i pass in the test function

from starlette.requests import Request

def test_get_area_returns_area_of_feature(client, user_1, monkeypatch):
    monkeypatch.setattr("app.utils.verify_sub_group.requester_sub","11bdd74a-90a1-455e-a2a8-64a0cad728ea")
    monkeypatch.setattr("app.utils.verify_sub_group.requester_group","users")

it points to the original(actual) function

so how can I monkeypatch with request.scope from starlette

this is the function that I need to mock

def verify_sub_group(sub: UUID, request: Request):
    """this function returns true if the group and uuid match with cognito uuid."""

    requester_sub = request.scope['aws.event']['requestContext']['authorizer']['claims']['sub']
    requester_group = request.scope['aws.event']['requestContext']['authorizer']['claims']['cognito:groups']

@Kludex I need your help here!!

[Kludex]

this is the function that I need to mock

Then why not mock that function directly? 🤔

What you want is to call AWS on the test suite, or...?

[rajshahdev]

Hi, I made one api endpoint that fetch the sub from starlette(through JWT token).
now when I tested this endpoint it calls the actual starlette request and not mocked one.

users.py

from starlette.requests import Request
@router.get("/sub")
async def get_sub(request: Request) -> Dict:
        sub = request.scope["aws.event"]["requestContext"]["authorizer"]["claims"]["sub"]

test_users.py

import pytest
from starlette.requests import Request

@pytest.fixture(scope='function')
def mocked_request_scope():
    scope = {
                "type": "http",
                "http_version": "1.1",
                "method": "http_method",
                "headers": "[[k.encode(), v.encode()] for k, v in headers.items()]",
                "path": "self.resolve_asgi_path(event, context)",
                "raw_path": "self.resolve_asgi_raw_path(event, context)",
                "root_path": "self.resolve_asgi_root_path(event, context)",
                "scheme": 'headers.get("x-forwarded-proto", "https")',
                "query_string": "query_string",
                "server": "server",
                "client": "client",
                "asgi": {"version": "3.0"},
                "aws.event" : 
                            {"requestContext": 
                                {"authorizer": 
                                    {"claims": 
                                        {
                                            "sub" : "11bdd74a-90a1-455e-a2a8-64a0cad728ea"
                                        }
                                    }
                                }
                            }
                }
    return scope

@pytest.fixture
def mocked_sub(monkeypatch, mocked_request_scope):
    monkeypatch.setattr("starlette.requests.Request.scope", mocked_request_scope)

def test_get_users(mocked_sub, client):
    response = client.get("/users/sub")
    content = response.json()
    print(content)
    assert response.status_code == 200

right now it is not pointing to mocked_request_scope the solution will probably be specific to starlette, which as I say I don't have enough context to solve.

[rajshahdev]

i am not able to mock the function directly as I am testing it using fastapi

[rajshahdev]

sorry, the question asked earlier was not descriptive, maybe this one gives you more context on what I want to say!!

[symroe]

FWIW I have the same requirements, more or less.

I have some middleware that looks for AWS Lambda Authorizer data in scope.

It feels like I should be able to change the content of scope according to the known values I'll see in Lambda. I've not found a way to do this, though.

Exposing scope on TestClient somehow would be handy, although I'm not sure that's the right place. Either way, some interface to alter the scope object from inside tests would be really useful.

For my case I ended up using Mangum in the tests. This gives me a fixed AWS-like scope, but I still can't test how my app reacts to this scope changing, so it's not an ideal situation.