matianfu

const chai = require('chai')
const expect = chai.expect

const hello = new require('stream').Writable({
  autoDestroy: true,

  destroy (err, callback) {
    console.log('6 before callback in _destroy')
    process.nextTick(() => console.log('i. before _destory callback nextTick'))
    callback(err)

matianfu

const hello = new require('stream').Writable({
  destroy (err, callback) {
    console.log('2 before callback in _destroy')
    callback(err)
    console.log('3 after callback in _destory')
  }
}).on('error', err => console.log('6 error'))
  .on('close', () => console.log('7 close'))

console.log('1 before destroy')

matianfu

// licensed under public domain
// author: matianfu@gmail.com

const EventEmitter = require('events')

// K combinator, not necessary, just for fun
const K = x => y => x

// this class is mainly for settle logic.
// the concrete class should emit a 'finish' event with err/data at the end of the process