🔗 Backend Integration
This frontend connects to a Node.js backend server running on port 3001. Make sure the backend is running before starting the frontend.
🚀 Available Scripts
- npm start - Start development server
- npm run build - Build for production
- npm test - Run test suite
- npm run eject - Eject from Create React App
🤝 Contributing
Feel free to submit issues and pull requests to improve the game!
# ♛ Chess Game Backend Server
A robust Node.js backend server powering real-time multiplayer chess games. Handles game logic, move validation, room management, and live player
communication.
## ⚡ Features
- 🏠 **Room Management** - Create and join game rooms with unique codes
- ♔ **Complete Chess Engine** - Full rule validation including special moves
- 🔄 **Real-time Sync** - Instant move broadcasting between players
- 🛡️ **Move Validation** - Server-side validation prevents cheating
- 👥 **Player Management** - Automatic color assignment and turn enforcement
- 🎯 **Game State Tracking** - Persistent game states across connections
- 📊 **Live Updates** - Check/checkmate/stalemate detection and broadcasting
## 🚀 Quick Start
```bash
# Install dependencies
npm install
# Start the server
node index.js
# Server runs on http://localhost:3001
🎮 Game Features
Core Chess Rules
- ✅ Piece Movement - All standard piece movements validated
- ✅ Castling - King and rook castling with proper validation
- ✅ En Passant - Pawn capture with position history tracking
- ✅ Pawn Promotion - Interactive promotion to any piece
- ✅ Check Detection - Real-time check status for both players
- ✅ Checkmate/Stalemate - Automatic game end detection
- ✅ Insufficient Material - Draw detection for impossible checkmates
Multiplayer Features
- 🎯 Room Codes - Join games with simple room identifiers
- 👥 Two Player Limit - Automatic room capacity management
- 🎨 Color Assignment - First player gets white, second gets black
- 🔄 Turn Enforcement - Server validates it's player's turn before moves
- 📱 Reconnection Handling - Graceful handling of disconnections
🏗️ Server Architecture
chessBackEnd/
├── index.js # Main server with Socket.IO handlers
├── Constants.js # Game state definitions and initial setup
├── Board/ # Chess board logic and helpers
├── Arbiters/ # Move validation and game rules
└── Reducer/ # Game state management actions
🔌 Socket.IO Events
Client → Server
- joinRoom(roomId) - Join a multiplayer game room
- makeMove(moveData) - Submit a chess move
- getValidMoves(piece) - Request valid moves for a piece
- setUpNewGame(roomId) - Start a new game in room
- promotePawn(promotion) - Select piece for pawn promotion
Server → Client
- playerColor({color}) - Assign player white/black
- board(gameState) - Send initial game setup
- moveResult({newPosition, turn}) - Broadcast move results
- checkStatus(status) - Update check/checkmate status
- validMoves(moves) - Send calculated valid moves
- openPromotionBox() - Trigger pawn promotion UI
- roomFull() - Notify when room is at capacity
🎯 API Endpoints
GET / # Health check endpoint
🔧 Tech Stack
- Node.js - JavaScript runtime
- Express.js - Web framework for HTTP server
- Socket.IO - Real-time bidirectional communication
- Chess.js - Chess game logic and validation library
- CORS - Cross-origin resource sharing configuration
📊 Game State Management
The server maintains three key data structures:
games = {} // roomId → {board, turn, castleDirection, oldPosition}
socketRoomMap = {} // socket.id → roomId
roomPlayers = {} // roomId → {w: socketId, b: socketId}
🛠️ Configuration
- Port: 3001 (configurable)
- CORS Origin: http://localhost:3000 (React frontend)
- Game Logic: Full chess rules with special move support
🔍 Debugging
The server includes comprehensive logging for:
- Player connections and room assignments
- Move validation and game state changes
- Check/checkmate detection
- Error handling and edge cases
🚀 Deployment
# Production deployment
npm install --production
node index.js
# Environment variables
PORT=3001 # Server port
CORS_ORIGIN=your-frontend # Frontend URL for CORS
🤝 Contributing
Submit issues and pull requests to help improve the chess engine!