owtlab-tracking/lib/utils/fetchRetry.js

A simple Tracking system

import 'promise-polyfill/src/polyfill';
import 'whatwg-fetch';
import configDefault from '../config-default.js';
// import Owtlab from '@owtlab/owtlab';

export default function (url, options) {
  const config = {
    ...configDefault,
    ...(options.retry || {}),
  };

  const retriesLimit = config.retry.limit;
  const retryInitialDelay = config.retry.initialDelay;
  const retryOn = config.retry.retryOnResponseStatuses;
  let retriesCount = 0;

  if (retryOn && !(retryOn instanceof Array)) {
    throw {
      name: 'ArgumentError',
      message: 'retryOn property expects an array',
    };
  }

  return new Promise(((resolve, reject) => {
    const wrappedFetch = function (n) {
      fetch(url, options)
        .then((response) => {
          if (retryOn.indexOf(response.status) === -1) {
            resolve(response);
          } else if (n > 0) {
            retry();
          } else {
            reject(response);
          }
        })
        .catch((error) => {
          if (n > 0) {
            retry();
          } else {
            reject(error);
          }
        });
    };

    function retry() {
      retriesCount += 1;
      setTimeout(() => {
        wrappedFetch(retriesLimit - retriesCount);
      }, 2 ^ (retriesCount * retryInitialDelay));
    }

    wrappedFetch(retriesLimit - retriesCount);
  }));
}