from fastapi import FastAPI from fastapi.testclient import TestClient app = FastAPI() items = {} @app.on_event("startup") async def startup_event(): items["foo"] = {"name": "Fighters"} items["bar"] = {"name": "Tenders"} @app.get("/items/{item_id}") async def read_items(item_id: str): return items[item_id] def test_read_items(): with TestClient(app) as client: response = client.get("/items/foo") assert response.status_code == 200 assert response.json() == {"name": "Fighters"}