# switch-stream

> A stream condition for switch/case
>
> [![NPM Version][npm-image]][npm-url]
> [![Download Status][download-image]][npm-url]
> [![Dependencies][david-image]][david-url]

### Usage

![switch.png](https://raw.githubusercontent.com/nuintun/switch-stream/master/images/switch.png)

```js
const switchStream = require('switch-stream');

process.in
  .pipe(
    switchStream(
      buf => {
        if (buf > 0) {
          return 'case1';
        } else if (buf < 0) {
          return 'case2';
        }
      },
      {
        case1: streamA,
        case2: streamB
      }
    )
  )
  .pipe(process.stdout);
```

If buf great than 0, then pipe to streamA. If buf less than 0, then pipe to streamB. Otherwise buf equal to 0, pipe to output directly.

### API

#### switchStream(switch, cases, options)

* switch

  Switch condition determine which case will be choose.
  Switch can be any type, if switch is function, it will be called.

* cases

  Choose which stream will be piped to by key switch return.

* options
  The stream options settings.

### Reference

Modify from popomore's [stream-switch](https://github.com/popomore/stream-switch), but use stream3.

[npm-image]: https://img.shields.io/npm/v/@nuintun/switch-stream.svg?style=flat-square
[npm-url]: https://www.npmjs.org/package/@nuintun/switch-stream
[download-image]: https://img.shields.io/npm/dm/@nuintun/switch-stream.svg?style=flat-square
[david-image]: http://img.shields.io/david/nuintun/switch-stream.svg?style=flat-square
[david-url]: https://david-dm.org/nuintun/switch-stream