merge2

Merge multiple streams into one stream in sequence or parallel.

[![NPM version][npm-image]][npm-url]
[![Build Status][travis-image]][travis-url]
[![Downloads][downloads-image]][downloads-url]

Install

Install with npm

``sh
npm install merge2
`

Usage

`js
const gulp = require('gulp')
const merge2 = require('merge2')
const concat = require('gulp-concat')
const minifyHtml = require('gulp-minify-html')
const ngtemplate = require('gulp-ngtemplate')

gulp.task('app-js', function () {
return merge2(
gulp.src('static/src/tpl/*.html')
.pipe(minifyHtml({empty: true}))
.pipe(ngtemplate({
module: 'genTemplates',
standalone: true
})
), gulp.src([
'static/src/js/app.js',
'static/src/js/locale_zh-cn.js',
'static/src/js/router.js',
'static/src/js/tools.js',
'static/src/js/services.js',
'static/src/js/filters.js',
'static/src/js/directives.js',
'static/src/js/controllers.js'
])
)
.pipe(concat('app.js'))
.pipe(gulp.dest('static/dist/js/'))
})
`

`js
const stream = merge2([stream1, stream2], stream3, {end: false})
//...
stream.add(stream4, stream5)
//..
stream.end()
`

`js
// equal to merge2([stream1, stream2], stream3)
const stream = merge2()
stream.add([stream1, stream2])
stream.add(stream3)
`

`js
// merge order:
// 1. merge stream1;
// 2. merge stream2 and stream3 in parallel after stream1 merged;
// 3. merge 'stream4' after stream2 and stream3 merged;
const stream = merge2(stream1, [stream2, stream3], stream4)

// merge order:
// 1. merge stream5 and stream6 in parallel after stream4 merged;
// 2. merge 'stream7' after stream5 and stream6 merged;
stream.add([stream5, stream6], stream7)
`

`js
// nest merge
// equal to merge2(stream1, stream2, stream6, stream3, [stream4, stream5]);
const streamA = merge2(stream1, stream2)
const streamB = merge2(stream3, [stream4, stream5])
const stream = merge2(streamA, streamB)
streamA.add(stream6)
`

API

`js
const merge2 = require('merge2')
`

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return a duplex stream (mergedStream). streams in array will be merged in parallel.

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return the mergedStream.

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It will emit 'queueDrain' when all streams merged. If you set end === false in options, this event give you a notice that should add more streams to merge or end the mergedStream.

#### stream

option
Type: Readable or Duplex or Transform stream.

#### options

option
Type: Object.

* end - Boolean - if end === false then mergedStream will not be auto ended, you should end by yourself. Default: undefined

* pipeError - Boolean - if pipeError === true then mergedStream will emit error event from source streams. Default: undefined

* objectMode - Boolean . Default: true

objectMode and other options(highWaterMark, defaultEncoding ...) is same as Node.js Stream`.

License

MIT © Teambition

[npm-url]: https://npmjs.org/package/merge2
[npm-image]: http://img.shields.io/npm/v/merge2.svg

[travis-url]: https://travis-ci.org/teambition/merge2
[travis-image]: http://img.shields.io/travis/teambition/merge2.svg

[downloads-url]: https://npmjs.org/package/merge2
[downloads-image]: http://img.shields.io/npm/dm/merge2.svg?style=flat-square