stream-all

Like Promise.all but for streams

installation

npm install stream-all

example

  var streamAll = require('stream-all')
  var through = require('through2')
 
  var addStream = function (x) {
    return through.obj(function (y, _, cb) {
      this.push(x + y)
      cb()
    })
  })
 
  var add1 = addStream(1)
  var add2 = addStream(2)
  var add3 = addStream(3)
 
  var allStream = streamAll([add1, add2, add3])
 
  allStream.on('data', function (data) {
    console.log(data)
  })
  allStram.on('end', function () {
    console.log('finished')
  })
 
  add1.write(1)
  add2.write(2)
  add3.write(3)
 
  // logs: [2, 4, 6]
 
  // if you close a stream it will always pass null as the value at that
  // streams index in the stramed array
 
  add1.destroy()
 
  add2.write(2)
  add3.write(3)
 
  // logs: [null, 4, 6]
 
  add2.destroy()
  add3.destroy()
 
  // logs: "finished"

api

streamAll ([streams])

streamAll takes an array of streams as its only parameter, and returns a readable stream that when read returns an array of the next readable value of all streams, where the value at index i is the next readable value from stream i in the original array passed to streamAll.

If some stream in [streams] closes before any of the others streamAll will always place a value of null at the stream's index in the returned array.

If some stream throws an error then streamAll will emit that error and will not return any further values.

streamAll closes once all streams that stream through it closes.

license

MIT