Retry jQuery AJAX requests with exponential backoff

ajax.js

import $ from 'jquery';
import uuidv4 from 'uuid/v4';

const wait = ms => $.Deferred(defer => setTimeout(defer.resolve, ms));

const request = (opts, numTries = 0) => {
  /*
   * Retry failed requests 2 additional times with exponential backoff
   */
  const RETRY_COUNT = 2;
  const INITIAL_NETWORK_RETRY_DELAY = 500;
  const delay = INITIAL_NETWORK_RETRY_DELAY + (INITIAL_NETWORK_RETRY_DELAY * numTries);

  let idempotencyKey;
  if (opts.type === 'POST' && !opts.idempotencyKey) {
    idempotencyKey = uuidv4();
  }

  const options = Object.assign({idempotencyKey}, opts)
  const $d = $.ajax(options);

  return $d.then(null, (xhr) => {
    if (xhr.readyState < 4 && numTries < RETRY_COUNT) {
      return wait(delay).then(() => request(options, numTries + 1));
    }
    return $d;
  });
};

Thanks for sharing. 🤝