Food Delivery Backend API

A complete RESTful Food Delivery backend API built as part of the ElifTech School Test Task.

Complexity Level: Advanced

Tech Stack

Technology	Purpose
Node.js + TypeScript	Runtime & language
NestJS	Web framework
Prisma	ORM / data access layer
MongoDB Atlas	Database
class-validator + class-transformer	Input validation & transformation
@nestjs/swagger	API documentation (OpenAPI)
@nestjs/config	Environment configuration

Features

• Full CRUD operations for Shops, Products, Orders, and Coupons
• Advanced product filtering (category, multi-category, sort), pagination
• Order creation with real-time price calculation and coupon discount
• Order history lookup by email + phone or order ID
• Coupon validation with active/inactive status
• Global input validation with descriptive error messages
• Consistent error response format ({ statusCode, message, error, path, timestamp })
• Swagger/OpenAPI documentation
• Database seeding script (idempotent)

Setup Instructions

1. Clone and Install

git clone <repo-url>
cd eliftech_backend
npm install

2. Configure Environment

Copy the example env file and fill in your MongoDB Atlas connection string:

cp .env.example .env

Edit .env:

DATABASE_URL="mongodb+srv://<username>:<password>@cluster0.mongodb.net/food-delivery?retryWrites=true&w=majority"
PORT=3000

3. Generate Prisma Client

npm run prisma:generate

4. Seed the Database

npm run prisma:seed

This will populate the database with:

• 6 shops (ratings from 2.5 to 4.8)
• 10 products per shop across categories (Burgers, Pizza, Drinks, Desserts, Sides)
• 5 coupons (4 active: SAVE10, WELCOME20, FIRST15, HALF50; 1 inactive: EXPIRED)

5. Start the Server

# Development (watch mode)
npm run start:dev

# Production
npm run build
npm run start:prod

The API will be available at: http://localhost:3000/api Swagger docs at: http://localhost:3000/api/docs

API Endpoints

Health

Method	Endpoint	Description
GET	/api/health	Service health check

Shops

Method	Endpoint	Description
GET	/api/shops	List all shops (optional: ?minRating=3&maxRating=5)
GET	/api/shops/:id	Get shop details by ID

Products

Method	Endpoint	Description
GET	/api/shops/:shopId/products	List products for a shop (supports category, sortBy, page, limit)
GET	/api/shops/:shopId/categories	List distinct product categories for a shop

Product Query Params:

• category — filter by category (comma-separated for multiple: Burgers,Pizza)
• sortBy — price_asc, price_desc, or name_asc
• page — page number (default: 1)
• limit — items per page (default: 10)

Orders

Method	Endpoint	Description
POST	/api/orders	Create a new order
GET	/api/orders/history	Get order history (?email=...&phone=... or ?orderId=...)
GET	/api/orders/:id	Get a single order by ID

Create Order Body:

{
  "customerName": "John Doe",
  "email": "john@example.com",
  "phone": "+380991234567",
  "address": "123 Main St, Kyiv",
  "shopId": "<shopObjectId>",
  "items": [
    { "productId": "<productObjectId>", "quantity": 2 }
  ],
  "couponCode": "SAVE10"
}

Coupons

Method	Endpoint	Description
GET	/api/coupons	List all active coupons
POST	/api/coupons/validate	Validate a coupon code ({ "code": "SAVE10" })

Available Coupon Codes (after seeding):

Code	Discount
SAVE10	10%
WELCOME20	20%
FIRST15	15%
HALF50	50%

Error Response Format

All errors return a consistent JSON structure:

{
  "statusCode": 404,
  "message": "Shop with id \"abc\" not found",
  "error": "Not Found",
  "path": "/api/shops/abc",
  "timestamp": "2026-03-28T10:00:00.000Z"
}

npm Scripts

Script	Description
npm run start	Start the server
npm run start:dev	Start in watch mode
npm run build	Build for production
npm run start:prod	Run production build
npm run prisma:generate	Generate Prisma client
npm run prisma:seed	Seed the database
npm run prisma:studio	Open Prisma Studio