from fastapi import APIRouter, FastAPI from starlette.requests import Request from starlette.responses import JSONResponse from starlette.testclient import TestClient app = FastAPI() router = APIRouter() @router.route("/items/") def read_items(request: Request): return JSONResponse({"hello": "world"}) app.include_router(router) client = TestClient(app) def test_sub_router(): response = client.get("/items/") assert response.status_code == 200 assert response.json() == {"hello": "world"}