@juzi/wechaty/src/pure-functions/retry-policy.ts

Wechaty is a RPA SDK for Chatbot Makers.

import {
  Policy,
  RetryPolicy,
}                 from 'cockatiel'
import {
  log,
}                 from '@juzi/wechaty-puppet'

/**
 * Create a retry policy that'll try whatever function we execute 3
 *  times with a randomized exponential backoff.
 *
 * https://github.com/connor4312/cockatiel#policyretry
 */
const retryPolicy = getRetryPolicy()

function getRetryPolicy (): RetryPolicy {
  const policy = Policy
    .handleAll()
    .retry()
    .attempts(3)
    .exponential({
      /**
       * ExponentialBackoff
       *  https://github.com/connor4312/cockatiel#exponentialbackoff
       */
      initialDelay : 1000,
      maxAttempts  : 5,
      maxDelay     : 10 * 1000,
    })

  policy.onRetry(reason => log.silly('wechaty',
    'retry-policy getRetryPolicy policy.onRetry() reason: "%s"',
    JSON.stringify(reason),
  ))
  policy.onSuccess(({ duration }) => log.silly('wechaty',
    'retry-policy getRetryPolicy policy.onSuccess(): retry call ran in %s ms',
    duration,
  ))
  return policy
}

const checkUntilChanged = async (gapMilliseconds: number, maxRetry: number, judgement: () => Promise<boolean> | boolean): Promise<boolean> => {
  let changed = await judgement()
  let currentTry = 1
  while (!changed && (currentTry < maxRetry)) {
    await new Promise(resolve => setTimeout(resolve, gapMilliseconds))
    changed = await judgement()
    currentTry++
  }
  return changed
}

export {
  retryPolicy,
  checkUntilChanged,
}