create-promises-for-promise-all.js

'use strict'

function * createPromises () {
  let max = 5
  for (let i = 0; i < max; ++i) {
    yield new Promise(done => {
      const to = Math.random() * i * 100
      setTimeout(() => {
        console.log('done %dms for i=%d', to, i)
        done(i)
      }, to)
    })
  }
}

const promises = createPromises()
const promise = Promise.all(promises)
promise.then(results => console.log('results', results))