UNO Game Simulation

A JavaScript UNO card game implementation with bot players, pluggable strategies, CLI simulation, and web UI.

Note

This project was vibe-coded largely over two hours in one sitting, on YouTube livestream

Web UI

Play UNO in your browser with an interactive web interface.

Quick Start

# Install dependencies
npm install

# Start development server
npm run dev

Then open http://localhost:5173 in your browser.

Production Build

# Build optimized production bundle
npm run build

# Preview production build
npm run preview

The production build outputs to dist/ with optimized assets (~55KB gzipped). The preview server runs on http://localhost:4173.

Features

• Spectator Mode: Watch bots play automatically
• Human Player Mode: Play against bots with full UI interaction
• 2-6 Players: Configurable player count with flexible positioning
• Wild Card Selection: Color picker modal for wild cards
• Special Cards: Skip, Reverse, Draw Two/Four with visual indicators
• Animation Controls: Toggle between instant and smooth animations
• Game Statistics: Winner display and Play Again functionality

Testing

# Run all E2E tests
npm run test:e2e

# Run against production build
BASE_URL=http://localhost:4173 npm run test:e2e

CLI Simulation

Run headless game simulations from the command line.

Quick Start

# Run a 2-player game
node simulate.js

# Run with 4 players
node simulate.js --players 4

# Verbose output showing each turn
node simulate.js --players 4 --verbose

# Run with multiple games
node simulate.js --count 10

Run Unit Tests

npm test

Project Structure

• src/game/ - Core game logic (Card, Deck, Player, Game, Rules)
• src/strategies/ - Bot AI strategies (BasicStrategy)
• src/report/ - Game statistics and reporting
• simulate.js - CLI entry point
• test/unit/ - Unit tests for all components
• test/integration/ - Full game simulation tests
• reports/ - Generated JSON reports from simulations

Implementation Details

Game Rules:

• 2-6 players, 7 cards dealt to each
• Match by color or value
• Action cards: Skip, Reverse, Draw Two, Wild, Wild Draw Four
• Stacking: +2 stacks on +2 only, +4 stacks on +4 only (no cross-stacking)
• Win by emptying your hand

Architecture:

• ES modules (Node.js)
• Strategy pattern for bot AI (easily extensible)
• Event-driven game loop for observability
• Automatic deck reshuffling when draw pile exhausted
• Full test coverage with Node.js built-in test runner

Reports: Generated after each game in reports/report.json with:

• Turn count and duration
• Winner
• Per-player stats (cards played/drawn, UNOs called, action/wild cards played)

Game Rules

See rules.md for complete UNO rules including stacking mechanics and edge cases.