ysjj-system/node_modules/stream-combiner/index.js

var duplexer = require('duplexer')

module.exports = function () {

  var streams = [].slice.call(arguments)
    , first = streams[0]
    , last = streams[streams.length - 1]
    , thepipe = duplexer(first, last)

  if(streams.length == 1)
    return streams[0]
  else if (!streams.length)
    throw new Error('connect called with empty args')

  //pipe all the streams together

  function recurse (streams) {
    if(streams.length < 2)
      return
    streams[0].pipe(streams[1])
    recurse(streams.slice(1))  
  }
  
  recurse(streams)
 
  function onerror () {
    var args = [].slice.call(arguments)
    args.unshift('error')
    thepipe.emit.apply(thepipe, args)
  }
  
  //es.duplex already reemits the error from the first and last stream.
  //add a listener for the inner streams in the pipeline.
  for(var i = 1; i < streams.length - 1; i ++)
    streams[i].on('error', onerror)

  return thepipe
}