worker.js

const promise1 = new Promise((resolve, reject) => {
  setTimeout(resolve, 100, 'one')
})

const promise2 = new Promise((resolve, reject) => {
  setTimeout(resolve, 200, 'two')
})

const promise3 = new Promise((resolve, reject) => {
  setTimeout(resolve, 300, 'three')
})

const promise4 = new Promise((resolve, reject) => {
  setTimeout(resolve, 400, 'four')
})

const promise5 = new Promise((resolve, reject) => {
  setTimeout(resolve, 500, 'five')
})

const promises = [promise1, promise2, promise3, promise4, promise5]

if (typeof importScripts === 'undefined') {
  let values = []
  let workers = window.navigator.hardwareConcurrency || 1
  for (let i = 0; i < workers; i++) {
    let worker = new Worker('index.js')
    worker.addEventListener('message', (msg) => {
    })
    worker.postMessage({i: i})
  }
} else {
  self.addEventListener('message', (msg) => {
    console.log(typeof importScripts, promises)
  }, false)
}