https://github.com/kaelzhang/express-to-koa

Use express middlewares in Koa2, the one that really works.
https://github.com/kaelzhang/express-to-koa

converter express koa koa2 middleware

Last synced: 2 months ago
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Use express middlewares in Koa2, the one that really works.

• Host: GitHub
• URL: https://github.com/kaelzhang/express-to-koa
• Owner: kaelzhang
• License: other
• Created: 2017-03-03T12:30:55.000Z (almost 8 years ago)
• Default Branch: master
• Last Pushed: 2019-07-05T02:40:00.000Z (over 5 years ago)
• Last Synced: 2024-04-15T12:32:58.344Z (8 months ago)
• Topics: converter, express, koa, koa2, middleware
• Language: JavaScript
• Homepage:
• Size: 32.2 KB
• Stars: 20
• Watchers: 4
• Forks: 5
• Open Issues: 1
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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# 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](https://www.npmjs.com/package/koa-connect)

- Handle express middlewares that contains `.pipe(res)`, such as `express.static` which based on [`send`](https://www.npmjs.com/package/send)

## Usage

```js

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](https://nodejs.org/dist/latest-v7.x/docs/api/http.html#http_class_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](https://www.npmjs.com/package/webpack-dev-middleware)

- [webpack-hot-middleware](https://www.npmjs.com/package/webpack-hot-middleware)

- [next.getRequestHandler()](https://github.com/zeit/next.js/#custom-server-and-routing)

- Other middlewares which are waiting for you to add to the README. Any contributions are welcome.

## License

MIT