code

• add native Promise.prototype.sleep
• just handle resolve
• reject will continue immediately

// sleep sleepTime ms, and pass rs on
// error will pass immediately
Promise.prototype.sleep = function(sleepTime) {
  return this.then(rs => {
    return new Promise(resolve => {
      setTimeout(() => {
        resolve(rs)
      }, sleepTime)
    })
  })
}

usage

first setup

• node: require('promise-sleep')
• es6: import 'promise-sleep'

and then, native Promise was patched

second use it

Promise.resolve('extend native')
.sleep(1000)
.then(function(rs) {
  console.log('after 1000ms, i got', rs);
})