Express Middleware

The Express plugin allows you to integrate Express.js-style middleware into your Minima.js application. This provides compatibility with the vast ecosystem of Express middleware while maintaining Minima.js's lightweight architecture.

Installation

The plugin is included with the @minimajs/server package and can be imported from @minimajs/server/plugins.

import { express } from "@minimajs/server/plugins/express";

Usage

Register Express-style middleware with your application instance. The middleware function receives the Node.js req and res objects, along with a next callback.

import { createApp } from "@minimajs/server";
import { express } from "@minimajs/server/plugins/express";

const app = createApp();

// Use Express middleware
app.register(
  express((req, res, next) => {
    console.log("Request URL:", req.url);
    next();
  })
);

Important Notes

Node.js Only

This plugin only works with Node.js servers. It requires access to the underlying IncomingMessage and ServerResponse objects from Node.js's HTTP module.

Examples

Using Third-Party Express Middleware

You can use existing Express middleware packages:

import helmet from "helmet";
import compression from "compression";

// Security headers
app.register(express(helmet()));

// Response compression
app.register(express(compression()));

Custom Middleware

Create custom Express-style middleware for specific needs:

app.register(
  express((req, res, next) => {
    // Add custom headers
    res.setHeader("X-Custom-Header", "MyValue");
    next();
  })
);

Error Handling

Pass errors to the Minima.js error handling system using the next callback:

app.register(
  express((req, res, next) => {
    try {
      // Some operation that might fail
      validateRequest(req);
      next();
    } catch (error) {
      next(error);
    }
  })
);

Type Definitions

export type ExpressCallback = (req: unknown, res: unknown, next: (err?: unknown) => void) => void;

The callback function signature matches Express.js middleware:

• req: The Node.js IncomingMessage object
• res: The Node.js ServerResponse object
• next: A callback to continue to the next middleware or pass an error

Integration with Minima.js Context

The Express middleware integrates with Minima.js's context system:

• req corresponds to ctx.incomingMessage
• res corresponds to ctx.serverResponse
• Errors passed to next() are handled by Minima.js's error handling system