Can an Express route handler be async?

Yes. You can await work like a store lookup inside it, then respond with JSON once the awaited values are ready.

How do I verify this API's behavior?

Run npm test, which uses supertest. Assert that a request for an existing user returns 200 with that user's order list.

Can I change the stores or the global handler?

No. Keep user.repo.ts, order.repo.ts, and the global handler in app.ts exactly as given. The only place you fill in is the single route inside registerUserOrdersRoutes.

User Orders Lookup API

Your task

Build an API that shows a user's order list. Find the user, find that user's orders, and respond with JSON. Complete the GET /users/:id/orders route inside registerUserOrdersRoutes. Note: find the user with userRepo.findUserById and the orders with orderRepo.findByUser.

Ground rules

•Register the route with router.get inside registerUserOrdersRoutes(router).
•Use the user and order stores (user.repo.ts, order.repo.ts) exactly as given.
•Leave the app's global error handler (the 4-argument middleware in app.ts) as is.

Not required

•Authentication, authorization, pagination, sorting.
•The store implementation (use the given in-memory repo as is).
•Database and external-service integration.

▶About this challenge

Complete an Express + TypeScript API that returns a user's order list. Inside the GET /users/:id/orders route, find the user and that user's orders and respond with JSON. Leave the stores and the app's global handler exactly as given and fill in just the one route.

An Express route handler can be synchronous or asynchronous (async). An async handler can await work — like a store lookup — before it responds. This problem is about building such a route: inside GET /users/:id/orders, await the user lookup and that user's orders, then respond with JSON. The habit that matters is wiring the awaited lookups through to a clean JSON response for the normal order list.

Can an Express route handler be async?: Yes. You can await work like a store lookup inside it, then respond with JSON once the awaited values are ready.
How do I verify this API's behavior?: Run npm test, which uses supertest. Assert that a request for an existing user returns 200 with that user's order list.
Can I change the stores or the global handler?: No. Keep user.repo.ts, order.repo.ts, and the global handler in app.ts exactly as given. The only place you fill in is the single route inside registerUserOrdersRoutes.

User Orders Lookup API

Your task

Ground rules

•Register the route with router.get inside registerUserOrdersRoutes(router).
•Use the user and order stores (user.repo.ts, order.repo.ts) exactly as given.
•Leave the app's global error handler (the 4-argument middleware in app.ts) as is.

Not required

•Authentication, authorization, pagination, sorting.
•The store implementation (use the given in-memory repo as is).
•Database and external-service integration.

▶About this challenge

Can an Express route handler be async?: Yes. You can await work like a store lookup inside it, then respond with JSON once the awaited values are ready.
How do I verify this API's behavior?: Run npm test, which uses supertest. Assert that a request for an existing user returns 200 with that user's order list.
Can I change the stores or the global handler?: No. Keep user.repo.ts, order.repo.ts, and the global handler in app.ts exactly as given. The only place you fill in is the single route inside registerUserOrdersRoutes.