Express.ts

A TypeScript-first, Express-like HTTP server framework with modern features and comprehensive testing.

Features

• 🚀 TypeScript-first with strict type safety
• 🛣️ Dynamic route parameters with {param} and :param syntax
• 📦 Built-in body parsing (JSON, form-encoded, raw)
• 🔧 Middleware support with error handling and prefix matching
• 🏭 Router support for modular route organization (Express.js style)
• 🧪 Comprehensive test suite (57+ tests, 100% coverage)
• ⚡ Express-like API for familiar development experience
• 🏗️ Modular architecture with clean separation of concerns

Requirements

• Node.js 18.0.0 or higher
• "type": "module" in your package.json (ES modules required)
• tsx recommended for TypeScript execution
• Linux/Unix environment for building from source (uses bash scripts and sed commands)
• TypeScript 5.8+ (for development)

Quick Start

Installation

Install from npm (recommended):

npm install @mouradisalah/express.ts
npm install --save-dev tsx @types/node typescript

Example package.json setup:

{
  "type": "module",
  "scripts": {
    "start": "tsx server.ts"
  },
  "dependencies": {
    "@mouradisalah/express.ts": "^1.0.5"
  },
  "devDependencies": {
    "tsx": "^4.20.3",
    "@types/node": "^24.1.0",
    "typescript": "^5.8.3"
  }
}

Or install from GitHub Packages (requires authentication):

npm install @mouradisalah/express.ts --registry=https://npm.pkg.github.com

Quick Start (Local Development)

# Clone the repository
git clone https://github.com/MouradiSalah/express.ts.git
cd express.ts
npm install
npm run build:check
npm run build
npm run dev
npm test

Usage

// Import for npm usage:
import { createApplication, createRouter } from '@mouradisalah/express.ts';

// Import for local development (if cloned):
// import { createApplication, createRouter } from './express';

const app = createApplication();

// Middleware
app.use((req, res, next) => {
  console.log(`${req.method} ${req.url}`);
  next();
});

// Routes with parameters (supports both {param} and :param)
app.get('/users/{id}', (req, res) => {
  res.json({ userId: req.params?.id });
});

app.get('/users/:id/:name', (req, res) => {
  res.json({
    id: req.params?.id,
    name: req.params?.name,
  });
});

// Router for modular organization (Express.js style)
const apiRouter = createRouter();

apiRouter.use((req, res, next) => {
  res.setHeader('X-API-Version', '1.0');
  next();
});

apiRouter.get('/status', (req, res) => {
  res.json({ status: 'active' });
});

app.use('/api', apiRouter);

// POST with body parsing
app.post('/users', (req, res) => {
  res.status(201).json({
    message: 'User created',
    user: req.body,
  });
});

// Start server
app.listen(3000, () => {
  console.log('🚀 Server running on http://localhost:3000');
});

API Reference

Application Methods

• app.get(path, handler) - Handle GET requests
• app.post(path, handler) - Handle POST requests
• app.put(path, handler) - Handle PUT requests
• app.patch(path, handler) - Handle PATCH requests
• app.delete(path, handler) - Handle DELETE requests
• app.use(middleware) - Add middleware
• app.listen(port, callback) - Start server

Route Parameters

You can use either {param} or :param syntax for dynamic routes:

// Both of these are valid and equivalent:
app.get('/users/{id}/posts/{postId}', (req, res) => {
  const id = req.params?.id;
  const postId = req.params?.postId;
  // Handle request
});

app.get('/users/:id/posts/:postId', (req, res) => {
  const id = req.params?.id;
  const postId = req.params?.postId;
  // Handle request
});

Body Parsing

Automatic body parsing for POST/PUT/PATCH requests:

app.post('/api/data', (req, res) => {
  // req.body contains parsed JSON, form data, or raw text
  console.log(req.body);
});

Middleware

// Logger middleware
app.use((req, res, next) => {
  console.log(`${req.method} ${req.url}`);
  next();
});

// Prefix-based middleware (Express.js style)
app.use('/api', (req, res, next) => {
  res.setHeader('X-API-Version', '1.0');
  next();
});

// Error handling middleware
app.use((req, res, next) => {
  try {
    next();
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

Router Support

Express.js-style router for modular route organization:

// userController.ts
import { createRouter } from '@mouradisalah/express.ts';

const userRouter = createRouter();

userRouter.use((req, res, next) => {
  console.log('User route accessed');
  next();
});

userRouter.get('/', (req, res) => {
  res.json({ users: [] });
});

userRouter.get('/{id}', (req, res) => {
  res.json({ user: { id: req.params?.id } });
});

export default userRouter;

// app.ts
import userRouter from './userController';

app.use('/api/users', userRouter);

Development

Prerequisites

• Node.js 18+
• npm 8+
• Linux/Unix environment (required for build process)

Build Requirements

Important: The build process requires a Linux/Unix environment due to:

• Bash shell scripts for ES module import fixing
• sed commands for post-build processing
• Unix-style file paths in build scripts

For Windows users:

• Use WSL (Windows Subsystem for Linux)
• Use Docker with a Linux container
• Use GitHub Actions or other Linux-based CI/CD for building

Setup

# Install dependencies
npm install

# Set up Git hooks (automatic code quality checks)
npm run prepare

Available Scripts

• npm run dev - Start development server with hot reload
• npm run build - Build TypeScript to JavaScript
• npm run test - Run all tests
• npm run test:watch - Run tests in watch mode
• npm run test:coverage - Generate coverage report
• npm run lint - Run ESLint
• npm run lint:fix - Fix linting issues automatically
• npm run format - Format code with Prettier
• npm run check - Run lint, format check, and tests

Code Quality

This project enforces strict code quality standards:

• Pre-commit hooks automatically lint and format code
• Pre-push hooks run the full test suite
• GitHub Actions validate all PRs with comprehensive CI/CD pipeline
• TypeScript strict mode with no any types allowed
• Jest testing with high coverage requirements

Architecture

src/
├── app.ts              # Main App class with HTTP methods
├── express.ts          # Factory function for Express-like API
├── index.ts            # Example server implementation
├── types/              # TypeScript type definitions
│   ├── application/    # Application interface
│   ├── handlers/       # Request/response handlers
│   ├── http/           # HTTP method and message types
│   └── routing/        # Route interface definitions
└── utils/              # Core utilities
    ├── route-parser.ts # Dynamic route parsing with {param} syntax
    └── body-parser.ts  # Request body parsing (JSON/form/raw)

Testing

The project includes comprehensive test coverage:

• Unit tests for all utilities and core classes
• Integration tests for complete API workflows
• Type validation tests for TypeScript interfaces
• Error handling tests for edge cases

# Run all tests
npm test

# Run with coverage
npm run test:coverage

# Run specific test file
npm test -- --testPathPattern=app.test.ts

Contributing

We welcome contributions! Please see CONTRIBUTING.md for detailed guidelines.

Quick Contribution Guide

1. Fork the repository
2. Create a feature branch: git checkout -b feature/amazing-feature
3. Make your changes (hooks will validate code quality)
4. Commit using conventional commits: git commit -m "feat: add amazing feature"
5. Push to your branch: git push origin feature/amazing-feature
6. Open a Pull Request

Commit Message Format

Use conventional commits with the provided template:

git config commit.template .gitmessage

License

This project is licensed under the MIT License.

Acknowledgments

• Inspired by Express.js but built with TypeScript-first principles
• Uses modern Node.js features and best practices
• Comprehensive testing approach inspired by industry standards