asyncAwait.js

function fakePromise(time, value) {
  return new Promise((resolve) => {
    setTimeout(()=>resolve(value), time)
  })
}

function* networkRequest() {
  const value = yield fakePromise(1000, 123)
  return yield fakePromise(1000, value + 123)
}

function await(generator, nextValue) {
  const {value, done} = generator.next(nextValue)
  if (done) { return value  }
  if (typeof value.then === 'function') {
    return value.then((result) => await(generator, result))
  } else {
    return value
  }
}


const async = networkRequest()
await(async).then(console.log)