javascript polling w\ Promise

pollProgress.js

pollProgress(timeout, interval) {
  let endTime = Number(new Date()) + (timeout || 3 * 1000 * 60)
  interval = interval || 1000
  let checkCondition = (resolve, reject) => {
    this.fetchProgress(this.progressToken)
      .then((response) => {
        if (response.data.percentage >= 100) {
          resolve(response)
        } else if (Number(new Date()) < endTime) {
          setTimeout(checkCondition, interval, resolve, reject)
        } else {
          reject(new Error('Poll timed out: ' + arguments))
        }
      }).catch(e => reject(e))
  }
  return new Promise(checkCondition)
},