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

Use a Koa/Express middleware in an Express/Koa app
https://github.com/xingxingted/koa-to-express

express koa

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Use a Koa/Express middleware in an Express/Koa app

• Host: GitHub
• URL: https://github.com/xingxingted/koa-to-express
• Owner: xingxingted
• License: mit
• Created: 2017-05-22T17:05:38.000Z (over 7 years ago)
• Default Branch: master
• Last Pushed: 2022-07-14T12:04:49.000Z (over 2 years ago)
• Last Synced: 2024-10-30T00:09:57.206Z (19 days ago)
• Topics: express, koa
• Language: JavaScript
• Homepage:
• Size: 104 KB
• Stars: 9
• Watchers: 0
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# koa-to-express

[![Build Status](https://travis-ci.org/xingxingted/koa-to-express.svg?branch=master)](https://travis-ci.org/xingxingted/koa-to-express)

[![codecov](https://codecov.io/gh/xingxingted/koa-to-express/branch/master/graph/badge.svg)](https://codecov.io/gh/xingxingted/koa-to-express)

[![npm version](https://badge.fury.io/js/koa-to-express.svg)](https://badge.fury.io/js/koa-to-express)

Use a **Koa/Express** middleware in an Express/Koa app.

It could convert a middleware to another form between Express and koa middleware.

## Requirement

Koa-to-express requires *[email protected]* and *[email protected]* or higher.

Node 7.6+ is required if you want to use ES2015's *async/await* syntax.

Please go to [[email protected]](https://github.com/xingxingted/koa-to-express/tree/1.x) if you want to use koa1.

## Installation

Npm 5.x

```

npm install koa-to-express [-P]

```

Others

```

npm install koa-to-express -S

```

## Usage

```

const k2e       = require('koa-to-express');

const koaMiddleware = (ctx, next) => {

    ctx.body = 'hello world';

    return next();

};

require('express')().use(k2e(koaMiddleware)).listen(3000);

// curl localhost:3000/

// output: hello world

```

## API

### koaToExpress[.koaToExpress]\(middleware)

- **middleware** : `Function|Array`

****

* Convert Koa middleware(s) into an Express middleware and return it.

* Note that the second parameter (usually named as "next") passed to the last one of the middlewares is `() => Promise.resolve()`, because the cascading categories between [Koa](https://github.com/koajs/koa/blob/master/docs/api/index.md#cascading) and [Express](http://expressjs.com/en/guide/writing-middleware.html) are different and the end of the rest Express middlewares executing can't be informed back.

* It means that, resolving or rejecting the Koa middleware(s), which will return a resolved or rejected promise, will call the next middleware (as calling the Express's `next()`) or throw out an error (as calling the `next(err)`).

### koaToExpress.expressToKoa(middleware)

- **middleware** : `Function|Array`

****

* Convert Express middleware(s) into a Koa middleware and return it.

## License

MIT