express-to-koa

Use express middlewares in Koa2 (not support koa1 for now), the one that REALLY WORKS.

• Handle koa2 http status code, which fixes the common issue that we always get 404 with koa-connect
• Handle express middlewares that contains .pipe(res), such as express.static which based on send

Usage

const e2k = require('express-to-koa')
 
// Some express middleware
const devMiddleware = require('webpack-dev-middleware')(compiler, {
  publicPath,
  quiet: true
})
 
const app = new Koa()
app.use(e2k(devMiddleware))

What Kind of Express Middlewares are Supported?

NEARLY ALL express middlewares built with best practices.

TL;NR

express-to-koa does not support all arbitrary express middlewares, but only for those who only uses Express-Independent APIs like res.write and res.end, i.e. the APIs that node http.ServerResponse provides.

However, if a middleware uses APIs like res.send or something, express-to-koa will do far too much work to convert those logic to koa2, which is not easier than creating both express and koa2 from 0 to 1.

So, it is a good practice to write framework-agnostic middlewares or libraries.

Supported Middlewares

• webpack-dev-middleware
• webpack-hot-middleware
• next.getRequestHandler()
• Other middlewares which are waiting for you to add to the README. Any contributions are welcome.

License

MIT