RetryQueue.js

import async from 'async'

export default class RetryQueue {
  constructor (strategy, opts = {}) {
    const options = Object.assign({
      times: 14,
      interval (retryCount) {
        return 1000 * Math.pow(2, retryCount)
      }
    }, opts)

    const retryableStrategy = async.retryable(options, strategy)
    this.queue = async.queue(retryableStrategy, 1)
  }

  push (task) {
    return new Promise((resolve, reject) => {
      return this.queue.push(task, (err, result) => {
        if (err) return reject(err)
        return resolve(result)
      })
    })
  }
}

RetryQueue.test.js

import test from 'ava'

import RetryQueue from '../retry-queue.js'

test('RetryQueue handles items', async t => {
  const strategy = async function (str) {
    return str.toUpperCase()
  }

  const queue = new RetryQueue(strategy)

  const result = await queue.push('my task')

  t.is(result, 'MY TASK')
})

test('RetryQueue retries failed items', async t => {
  let tryCount = 0
  const strategy = async function (str) {
    if (tryCount < 5) {
      tryCount += 1
      throw new Error('Too few fails')
    }
    return str.toUpperCase()
  }

  const queue = new RetryQueue(strategy, { interval: 50 })

  const result1 = await queue.push('one')
  const result2 = await queue.push('two')

  t.is(result1, 'ONE')
  t.is(result2, 'TWO')
  t.is(tryCount, 5)
})