URL Shortener Service

A high-performance URL shortening service built with Node.js, TypeScript, Express, and MongoDB. This service provides both REST API and tRPC endpoints for creating short URLs and redirecting users to original URLs.

🚀 Features

• URL Shortening: Convert long URLs to short, manageable links
• Click Tracking: Monitor how many times each short URL has been accessed
• High Performance: Redis caching for improved response times
• Multiple API Interfaces:
  • REST API (v1 and v2)
  • tRPC for type-safe API calls
• Base62 Encoding: Efficient short URL generation using base62 encoding
• Comprehensive Logging: Winston logger with daily rotation
• Error Handling: Centralized error handling with correlation IDs
• Database Indexing: Optimized MongoDB queries with proper indexing
• Type Safety: Full TypeScript implementation with Zod validation

🛠️ Tech Stack

• Runtime: Node.js with TypeScript
• Framework: Express.js
• Database: MongoDB with Mongoose ODM
• Caching: Redis
• API: tRPC for type-safe APIs
• Validation: Zod schema validation
• Logging: Winston with daily rotation
• Development: Nodemon for hot reloading

📋 Prerequisites

Before running this application, make sure you have the following installed:

• Node.js (v16 or higher)
• MongoDB (local or cloud instance)
• Redis (local or cloud instance)

🚀 Quick Start

1. Clone the Repository

git clone <repository-url>
cd urlShortner/backend

2. Install Dependencies

npm install

3. Environment Setup

Create a .env file in the backend directory with the following variables:

PORT=3001
MONGO_URI=mongodb://localhost:27017/short_my_url
REDIS_URL=redis://localhost:6379
Redis_COUNTER_KEY=urlShortnerCounter
BASE_URL=http://localhost:3001

4. Start the Application

Development mode:

npm run dev

Production mode:

npm start

The server will start on http://localhost:3001

📚 API Documentation

Postman Collection

📋 Complete API Collection: URL Shortener API Collection

Import this collection into Postman to test all available endpoints with pre-configured requests.

Available Endpoints

tRPC Endpoints

• Create Short URL: POST /trpc/url.create
• Get Original URL: GET /trpc/url.getOrginalUrl

REST API Endpoints

• Health Check: GET /api/v1/ping
• URL Redirection: GET /:shortUrl

REST API v2

The v2 router is available at /api/v2 for future API versions.

🏗️ Project Structure

backend/
├── src/
│   ├── config/           # Configuration files
│   │   ├── db.ts        # MongoDB connection
│   │   ├── redis.ts     # Redis connection
│   │   ├── index.ts     # Server configuration
│   │   └── logger.config.ts # Winston logger setup
│   ├── controllers/     # Request handlers
│   │   ├── url.controller.ts # URL operations
│   │   └── ping.controller.ts # Health check
│   ├── middlewares/     # Express middlewares
│   │   ├── correlation.middleware.ts # Request correlation
│   │   └── error.middleware.ts # Error handling
│   ├── models/          # Database models
│   │   └── url.model.ts # URL schema
│   ├── repository/      # Data access layer
│   │   ├── url.repository.ts # URL database operations
│   │   └── cache.repository.ts # Redis cache operations
│   ├── routers/         # Route definitions
│   │   ├── trpc/        # tRPC router
│   │   ├── v1/          # API v1 routes
│   │   └── v2/          # API v2 routes
│   ├── service/         # Business logic
│   │   └── url.service.ts # URL shortening logic
│   ├── utils/           # Utility functions
│   │   ├── base62.ts    # Base62 encoding/decoding
│   │   └── errors/      # Custom error classes
│   ├── validators/      # Input validation schemas
│   └── server.ts        # Express server setup
├── logs/                # Application logs
├── package.json         # Dependencies and scripts
└── tsconfig.json        # TypeScript configuration

🔧 Configuration

Environment Variables

Variable	Description	Default
PORT	Server port	3001
MONGO_URI	MongoDB connection string	mongodb://localhost:27017/short_my_url
REDIS_URL	Redis connection string	redis://localhost:6379
Redis_COUNTER_KEY	Redis key for URL counter	urlShortnerCounter
BASE_URL	Base URL for short links	http://localhost:3001

Database Schema

The URL model includes:

• orginalUrl: The original long URL
• shortUrl: The generated short URL identifier
• clicks: Number of times the URL has been accessed
• createdAt: URL creation timestamp
• updatedAt: Last update timestamp

🚀 Performance Features

• Redis Caching: Frequently accessed URLs are cached in Redis
• Database Indexing: Optimized queries with indexes on shortUrl and createdAt
• Base62 Encoding: Efficient short URL generation
• Connection Pooling: Optimized database connections

📊 Logging

The application uses Winston for logging with:

• Daily log rotation
• Different log levels (error, warn, info, debug)
• Structured logging with correlation IDs
• Log files stored in the logs/ directory

🛡️ Error Handling

• Centralized error handling middleware
• Custom error classes for different error types
• Correlation IDs for request tracking
• Graceful error responses

🧪 Development

Available Scripts

• npm run dev: Start development server with hot reload
• npm start: Start production server

🤝 Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Submit a pull request

📄 License

This project is licensed under the ISC License.