Integrating Express with VitePress

VitePress is an excellent static site generator built on top of Vite, perfect for creating documentation and blog sites. However, there might be times when you need to add server-side functionality to your VitePress site. In this post, we’ll explore how to integrate Express.js with VitePress using a custom Vite plugin.

Why Integrate Express with VitePress?

While VitePress is primarily designed for static site generation, there are several scenarios where you might want to add server-side functionality:

• Creating API endpoints for dynamic data
• Handling form submissions
• Implementing authentication
• Managing server-side state
• Integrating with databases

Setting Up the Express Plugin

First, let’s create a custom Vite plugin that will integrate Express with our VitePress application.

1. Create the Express Plugin

Create a new file docs/.vitepress/plugins/express.js:

import express from 'express'
import cors from 'cors'

export function createExpressPlugin(options = {}) {
  const {
    corsOptions = {
      origin: '*',
      methods: ['GET', 'POST', 'PUT', 'DELETE', 'OPTIONS'],
      allowedHeaders: ['Content-Type', 'Authorization'],
    },
  } = options

  return {
    name: 'vite-plugin-express',
    configureServer(server) {
      const app = express()

      // Enable CORS
      app.use(cors(corsOptions))

      // Parse JSON bodies
      app.use(express.json())

      // Example route
      app.get('/api/hello', (req, res) => {
        res.json({ message: 'Hello from Express!' })
      })

      // Use Express as middleware in Vite’s server
      server.middlewares.use(app)
    },
  }
}

2. Configure VitePress

Update your docs/vite.config.js to use the Express plugin:

import { createExpressPlugin } from './.vitepress/plugins/express'

export default {
  plugins: [
    createExpressPlugin({
      corsOptions: {
        origin: 'http://localhost:5173', // VitePress default port
        methods: ['GET', 'POST', 'PUT', 'DELETE', 'OPTIONS'],
        allowedHeaders: ['Content-Type', 'Authorization'],
      },
    }),
  ],
}

How It Works

The integration works by:

1. Creating a custom Vite plugin that initializes an Express application
2. Using Vite’s middleware system to integrate Express with the development server
3. Running Express routes on the same port as VitePress (default: 5173)

Testing the Integration

1. Start your VitePress development server:

npm run docs:dev

2. Access the example API endpoint at:

http://localhost:5173/api/hello

You should receive a JSON response:

{
  "message": "Hello from Express!"
}

Adding Custom Routes

You can add your own routes by modifying the createExpressPlugin function. Here’s an example of adding a POST endpoint:

app.post('/api/submit', (req, res) => {
  const data = req.body
  // Process the data
  res.json({ success: true, data })
})

Benefits of This Approach

1. Single Port: Everything runs on the same port, simplifying development
2. No CORS Issues: Since everything is served from the same origin, you avoid CORS complications
3. Easy Deployment: Only one server to manage
4. Development Convenience: Hot module replacement works seamlessly with both VitePress and Express

Considerations

• This setup is primarily for development. For production, you might want to consider:
  • Running Express as a separate service
  • Using a reverse proxy (like Nginx)
  • Implementing proper security measures
• Remember that VitePress is still a static site generator, so this integration is most useful during development or when you need specific server-side functionality

Conclusion

Integrating Express with VitePress using a custom Vite plugin provides a powerful way to add server-side functionality to your documentation site. This approach maintains the simplicity of VitePress while giving you the flexibility to add dynamic features when needed.

Remember to check out the VitePress documentation and Express.js documentation for more information about both technologies.