SplitEase - Expense Splitting Made Simple

🚀 Overview

SplitEase is a full-stack expense management application designed to simplify the process of splitting expenses among friends, roommates, or travel groups. This repository contains the backend codebase built with Node.js, Express, and MongoDB.

Check out the Frontend Repository

✨ Features

• 📱 User Management

  • Register, login, and profile management
  • Social login with Google OAuth
  • Upload profile pictures to Cloudinary
  • Add and manage payment methods

• 👥 Group Management

  • Create groups for different expense categories
  • Add/remove friends to groups
  • Track group-specific expenses

• 💸 Expense Tracking

  • Add expenses with multiple splitting methods:
    • Equal splits
    • Percentage-based splits
    • Custom amount splits
  • Support for multiple currencies
  • Categorize expenses (Food, Transportation, etc.)

• 📊 Transaction Management

  • View pending payments
  • Settle transactions with transaction history
  • Track payment statuses

• 📈 Dashboard Analytics

  • Expense summaries
  • Group statistics
  • Monthly trends and category breakdowns

🔧 Tech Stack

Core Technologies

• Runtime: Node.js
• Framework: Express.js
• Database: MongoDB with Mongoose ODM
• Caching: Redis (Upstash)
• Authentication: JWT, Passport.js (Google OAuth)

Key Libraries

• Security: bcryptjs, helmet, cors
• File Uploads: multer, cloudinary
• Email: nodemailer
• Scheduling: node-cron
• Testing: Jest, Supertest

External Services

• Database Hosting: MongoDB Atlas
• Cloud Storage: Cloudinary
• Redis Cache: Upstash
• Currency Exchange: ExchangeRates API

🏗️ Architecture

SplitEase follows a robust, service-oriented architecture:

├── config/             # Configuration files
├── middleware/         # Express middleware
├── models/             # Mongoose models
├── routes/             # Express routes
├── services/           # Business logic
├── tests/              # Jest test suite
└── utils/              # Utility functions

Key Components:

• Models: Define the data structure
• Routes: Handle HTTP requests
• Services: Implement business logic
• Middleware: Process requests (auth, validation, file uploads)

💾 Database Schema

SplitEase uses MongoDB with the following main collections:

• Users: Profile information, payment methods, friends list
• Groups: Group details and member references
• Expenses: Expense records with splitting information
• Transactions: Payment tracking between users
• ExchangeRates: Currency conversion rates (cached daily)

🛡️ Security Features

• Password Hashing: bcrypt with 12 rounds of salting
• JWT Authentication: 7-day expiry tokens
• CORS Protection: Configured for allowed origins
• Rate Limiting: Prevents brute-force attacks
• Secure Headers: Using Helmet.js
• Password Reset: Secure token-based process

📡 API Endpoints

Authentication

• POST /api/auth/signup - Register new user
• POST /api/auth/login - Login existing user
• GET /api/auth/google/login - Google OAuth login
• POST /api/auth/forgot-password - Request password reset
• POST /api/auth/reset-password - Reset password with token

Profile

• GET /api/profile/me - Get user profile
• PUT /api/profile/update - Update profile details
• POST /api/profile/upload - Upload profile picture
• PUT /api/profile/change-password - Change password
• POST /api/profile/add-friend - Add a friend
• POST /api/profile/search-friends - Search for users by name
• POST /api/profile/add-payment - Add payment method
• DELETE /api/profile/delete-friend/:friendId - Remove a friend
• DELETE /api/profile/delete-payment/:paymentId - Remove payment method

Groups

• POST /api/groups/create - Create a new group
• GET /api/groups/mygroups - Get user's groups
• GET /api/groups/:groupId - Get group details
• PUT /api/groups/edit/:groupId - Edit group
• DELETE /api/groups/delete/:groupId - Delete group
• GET /api/groups/friends - Get user's friends

Expenses

• POST /api/expenses/create - Create a new expense
• GET /api/expenses/group/:groupId - Get group expenses
• GET /api/expenses/my-expenses - Get user expenses
• GET /api/expenses/expense/:expenseId - Get expense details
• DELETE /api/expenses/delete/:expenseId - Delete expense
• GET /api/expenses/summary - Get expense summary
• GET /api/expenses/recent - Get recent expenses
• GET /api/expenses/breakdown/:currency - Get expense breakdown by category

Transactions

• GET /api/transactions/pending - Get pending transactions
• GET /api/transactions/history - Get transaction history
• PUT /api/transactions/:transactionId/settle - Settle a transaction

Dashboard

• GET /api/stats - Get dashboard statistics
• GET /api/transactions/recent - Get recent transactions

🚦 Getting Started

Prerequisites

• Node.js (v14+)
• MongoDB (local or Atlas)
• Redis (optional but recommended)
• Google OAuth credentials (for social login)
• Cloudinary account (for image uploads)
• ExchangeRates API key

Environment Variables

Create a .env file in the root directory with the following:

PORT=5000
FRONTEND_URL=https://your-frontend-url.com
BACKEND_GOOGLE_CALLBACK_URL=https://your-backend-url.com/api/auth/google/callback
EMAIL_USER=your-email@gmail.com
EMAIL_PASS=your-app-password

MONGO_URI=mongodb+srv://username:password@cluster.mongodb.net/splitease
REDIS_URL=rediss://default:password@your-redis-url.upstash.io:6379
JWT_SECRET=your-jwt-secret-key

CLOUDINARY_CLOUD_NAME=your-cloud-name
CLOUDINARY_API_KEY=your-api-key
CLOUDINARY_API_SECRET=your-api-secret

GOOGLE_CLIENT_ID=your-google-client-id
GOOGLE_CLIENT_SECRET=your-google-client-secret

EXCHANGE_RATE_URL=https://api.apilayer.com/exchangerates_data/latest
EXCHANGERATES_API_KEY=your-api-key
BASE_CURRENCY=INR

Installation

# Clone the repository
git clone https://github.com/CodeTirtho97/SplitEase_backend.git

# Navigate to the directory
cd SplitEase_backend

# Install dependencies
npm install

# Run development server
npm run dev

# Run tests
npm test

🧪 Testing

SplitEase uses Jest for testing:

# Run all tests
npm test

# Run specific test file
npx jest tests/auth.test.js

The test suite includes:

• Authentication tests
• Profile management tests
• Group operations tests
• Expense and transaction tests

🔄 CI/CD Pipeline

This project supports continuous integration with:

• Jest test automation
• Custom test sequencer for dependency ordering
• In-memory MongoDB for test isolation

📜 License

This project is licensed under the ISC License.

👥 Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

📞 Contact

For questions or feedback, please reach out to the project maintainer:

• GitHub: CodeTirtho97
• LinkedIn: CodeTirtho97
• Twitter: CodeTirtho97

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Made with ❤️ by CodeTirtho97