Order Service

An order management REST API with authentication, role-based access control, and MongoDB persistence. It exposes endpoints for:

• Auth – register/login, issue JWTs
• Products – admin-only create/update, public list
• Orders – customers create/list/pay/cancel orders
• Users – admin-only user listing

Built with Node.js, Express 5, TypeScript, and Mongoose.

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1. Setup & Installation

• Prerequisites

  • Node.js: v20+ recommended
  • Package manager: pnpm (project uses pnpm-lock.yaml)
  • MongoDB: running locally or accessible via connection string

• Clone and install

git clone <your-fork-or-repo-url> order-service
cd order-service
pnpm install

• Build the project

pnpm run build

• Start the server

By default the compiled server entrypoint is dist/server.js:

node dist/server.js

The API will listen on http://localhost:<PORT> (defaults to 3000).

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2. Environment Variables

Environment variables are loaded via dotenv in src/config/env.ts. The following variables are required/recommended:

• Required

  • MONGO_URI: MongoDB connection string
    Example: mongodb://localhost:27017/order_service
  • JWT_SECRET: Secret key used to sign JWT access tokens

• Optional

  • PORT: HTTP port to run the server on
    Default: 3000
  • NODE_ENV: development | production
    Default: development
  • API_URL: External base URL for the API
    Default: http://localhost:3000
  • JWT_EXPIRES_IN: Token lifetime, e.g. 1h, 7d
    Default: 1h

• Example .env

NODE_ENV=development
PORT=3000
API_URL=http://localhost:3000

MONGO_URI=mongodb://localhost:27017/order_service

JWT_SECRET=super-secret-change-me
JWT_EXPIRES_IN=1h

Create a .env file at the project root before running the server or scripts.

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3. Database, Migrations & Seeding

This project uses MongoDB + Mongoose. There is no formal migration tool configured; schemas are defined via Mongoose models under src/models.

• Database connection

  • Configured in src/config/db.ts using MONGO_URI.

• Seeding products

There is a seed script at src/scripts/seed.ts which:

• Connects to MongoDB
• Clears the products collection
• Inserts a fixed list of sample products (mice, keyboards, etc.)

Run the seed script:

pnpm run seed

Under the hood this will:

1. Compile TypeScript (tsc)
2. Run node dist/scripts/seed.js

Make sure:

• The project is built without errors.
• MONGO_URI is correctly set in your .env.

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4. Running the Service

• Build once:

pnpm run build

• Start server:

node dist/server.js

The service will:

• Connect to MongoDB.
• Expose health check at GET /health.
• Expose REST endpoints under /auth, /products, /orders, /users.
• Expose Swagger docs under /docs.

Note: For local development you can also use ts-node / nodemon if you wire custom scripts, but for this task the build‑then‑run flow above is sufficient.

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5. API Reference & Example curl Requests

5.1 Health Check

• GET /health

curl -i https://order-service-t77z.onrender.com/health

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5.2 Auth

Register

• POST /auth/register
• Body:

curl -i -X POST https://order-service-t77z.onrender.com/auth/register \
  -H "Content-Type: application/json" \
  -d '{
    "email": "[email protected]",
    "password": "Password123",
    "role": "customer"
  }'

For an admin user, set "role": "admin".

Login

• POST /auth/login

curl -i -X POST https://order-service-t77z.onrender.com/auth/login \
  -H "Content-Type: application/json" \
  -d '{
    "email": "[email protected]",
    "password": "Password123"
  }'

The response includes a token field (JWT). Use this token in subsequent requests:

Authorization: Bearer <token>

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5.3 Products

List products (public)

• GET /products

curl -i https://order-service-t77z.onrender.com/products

Create product (admin only)

• POST /products

curl -i -X POST https://order-service-t77z.onrender.com/products \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer <admin-token>" \
  -d '{
    "name": "New Gadget",
    "price": 1999,
    "stock": 25
  }'

Update product (admin only)

• PATCH /products/:id

curl -i -X PATCH https://order-service-t77z.onrender.com/products/<productId> \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer <admin-token>" \
  -d '{
    "price": 2499,
    "stock": 40
  }'

---

5.4 Orders

Create order (customer or admin)

• POST /orders

curl -i -X POST https://order-service-t77z.onrender.com/orders \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer <token>" \
  -d '{
    "items": [
      { "productId": "<productId>", "quantity": 2 },
      { "productId": "<otherProductId>", "quantity": 1 }
    ]
  }'

List my orders

• GET /orders

curl -i https://order-service-t77z.onrender.com/orders \
  -H "Authorization: Bearer <token>"

Pay for an order

• POST /orders/:id/pay

curl -i -X POST https://order-service-t77z.onrender.com/orders/<orderId>/pay \
  -H "Authorization: Bearer <token>"

Cancel an order

• POST /orders/:id/cancel

curl -i -X POST https://order-service-t77z.onrender.com/orders/<orderId>/cancel \
  -H "Authorization: Bearer <token>"

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5.5 Users (Admin only)

List users

• GET /users

curl -i https://order-service-t77z.onrender.com/users \
  -H "Authorization: Bearer <admin-token>"

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6. Swagger / API Docs

The service is wired with swagger-jsdoc and swagger-ui-express. OpenAPI annotations live in the route files (e.g. src/routes/auth.routes.ts, src/routes/order.routes.ts, etc) and are aggregated in the Swagger configuration.

• View documentation UI:

open https://order-service-t77z.onrender.com/docs

This provides an interactive UI for exploring and testing all endpoints.

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7. Design Notes

• Architecture

  • Layered structure:
    • controllers/: Express route handlers (request/response orchestration).
    • services/: Business logic (auth, orders, products, users).
    • repositories/: Data access layer over Mongoose models.
    • models/: Mongoose schemas and models.
    • middleware/: Cross-cutting concerns (auth, validation, error handling, rate limiting, role checks).
  • Separation of concerns keeps controllers thin and business logic testable.

• Authentication & Authorization

  • JWT-based auth (see auth.middleware.ts and utils/jwt.ts).
  • Role-based access control via requireRole middleware:
    • Customers can create/list/pay/cancel their own orders.
    • Admins can manage products and list all users.

• Validation & Error Handling

  • Zod schemas validate payloads (validation/*.schema.ts).
  • Central error.middleware.ts normalizes API error responses.
  • rateLimit.middleware.ts limits sensitive endpoints (e.g. auth) to mitigate brute-force.

• Persistence

  • MongoDB via Mongoose models (user.model.ts, product.model.ts, order.model.ts).
  • Order items reference products and store quantities and pricing data for consistency.

• Observability & DX

  • morgan + custom logger provide structured request logs.
  • TypeScript configuration (tsconfig.json) and linting (eslint.config.mts) encourage a consistent, safe codebase.

This design aims to emulate a production-style order service that is still compact enough to reason about in an interview setting while showcasing authentication, authorization, validation, error handling, and data modeling.