express-route-enforcer 🔒

Enhanced Express routing with strict HTTP compliance, security best practices, and parameterized route support.

Features ✨

• 🚦 Proper HTTP Compliance: 404/405 responses with Allow headers
• 🔐 Security First: Auto-configured helmet & CORS
• 🎯 Parametrized Routes: Full Express-style path parameter support
• 📝 Structured Config: Centralized route declaration
• 🚨 Standardized Errors: Consistent JSON error format
• ⚡ Performance Optimized: Precompiled route matching
• 🧪 Validation: Runtime config checks during startup

Installation 📦

npm install express-route-enforcer

Peer Dependencies:

npm install express helmet cors http-errors path-to-regexp

Quick Start 🚀

const express = require('express');
const { createRouteEnforcer, createErrorHandler } = require('express-route-enforcer');

const app = express();
app.use(express.json());

// Route Configuration
const routeConfig = [
  {
    path: '/api/users/:id',
    methods: ['GET', 'PUT'],
    middlewares: [
      (req, res, next) => {
        console.log('Accessing user:', req.params.id);
        next();
      },
      (req, res) => res.json({ user: { id: req.params.id } })
    ]
  }
];

// Initialize Enforcer
const enforcer = createRouteEnforcer(app, routeConfig, {
  helmetOptions: { contentSecurityPolicy: false },
  corsOptions: { origin: 'https://trusted-domain.com' }
});

app.use(enforcer);
app.use(createErrorHandler({ includeStack: true }));

app.listen(3000, () => {
  console.log('Server running on port 3000');
});

Configuration ⚙️

Route Configuration Schema

interface RouteConfig {
  path: string;           // Express-style path
  methods: string[];      // HTTP methods (case-insensitive)
  middlewares: Function[];// Array of Express middleware functions
}

Security Options

createRouteEnforcer(app, routeConfig, {
  helmetOptions: { ... },  // Custom helmet configuration
  corsOptions: { ... }     // Custom CORS configuration
});

Error Handling 🚨

Standard Error Format:

{
  "error": {
    "message": "Method PATCH not allowed",
    "status": 405,
    "timestamp": "2024-02-20T14:30:00.000Z",
    "stack": "..." // Optional in development
  }
}

Customization:

app.use(createErrorHandler({
  includeStack: process.env.NODE_ENV === 'development'
}));

Advanced Usage 🧠

Parameterized Routes

{
  path: '/books/:genre/:author?',
  methods: ['GET'],
  middlewares: [(req, res) => {
    res.json({
      genre: req.params.genre,
      author: req.params.author || 'unknown'
    });
  }]
}

Wildcard Methods

{
  path: '/health',
  methods: ['ALL'], // Handles any HTTP method
  middlewares: [healthCheckHandler]
}

Custom Security Policies

createRouteEnforcer(app, routes, {
  helmetOptions: {
    contentSecurityPolicy: {
      directives: {
        defaultSrc: ["'self'"],
        scriptSrc: ["'self'", "trusted-cdn.com"]
      }
    }
  },
  corsOptions: {
    origin: [/\.example.com$/, 'https://partner.site'],
    methods: ['GET', 'POST']
  }
});

Performance Considerations ⚡

1. Precompiled Routes:
   Routes are compiled to regex during initialization for faster matching.

2. Method Caching:
   Allowed methods are cached using Set operations for O(1) lookups.

3. Benchmarking:
   Use tools like autocannon for load testing:

   npx autocannon -c 100 -d 20 http://localhost:3000/api

API Reference 📚

createRouteEnforcer(app, routeConfig, options)

• app: Express application instance
• routeConfig: Array of route configurations
• options:
  • helmetOptions: Custom helmet configuration
  • corsOptions: Custom CORS configuration

createErrorHandler(options)

• options:
  • includeStack: Include error stack traces (default: false)

Comparison vs Express Native 📊

| Feature | Express Native | express-route-enforcer | |------------------------|----------------|------------------------| | 405 Method Handling | ❌ | ✅ | | Security Headers | Manual | ✅ Auto | | Route Validation | ❌ | ✅ Pre-startup | | Parametrized Routes | ✅ | ✅ Enhanced | | Error Formatting | Manual | ✅ Standardized | | CORS Support | Manual | ✅ Integrated |

Testing 🧪

const request = require('supertest');

describe('User API', () => {
  it('GET /api/users/123 returns 200', async () => {
    await request(app)
      .get('/api/users/123')
      .expect(200)
      .expect(res => {
        assert(res.body.user.id === '123');
      });
  });

  it('DELETE /api/users/123 returns 405', async () => {
    const res = await request(app)
      .delete('/api/users/123')
      .expect(405);
      
    assert(res.headers.allow.includes('GET, PUT'));
  });
});

Contributing 🤝

1. Fork the repository
2. Create feature branch (git checkout -b feature/improvement)
3. Commit changes (git commit -am 'Add amazing feature')
4. Push to branch (git push origin feature/improvement)
5. Open Pull Request

License 📄

MIT © [Dannys-notepad]

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