Long Polling in React Native

gistfile1.js

/*--- LONG POLL  --*/
/**
 * Adapted from http://blog.gospodarets.com/fetch_in_action/
 * many thanks!
 */

var MAX_WAITING_TIME = 5000;// in ms

var getJSON = function (params) {
  var wrappedPromise = {};
  var promise = new Promise(function (resolve, reject) {
    wrappedPromise.resolve = resolve;
    wrappedPromise.reject = reject;
  });
  wrappedPromise.then = promise.then.bind(promise);
  wrappedPromise.catch = promise.catch.bind(promise);
  wrappedPromise.promise = promise;// e.g. if you want to provide somewhere only promise, without .resolve/.reject/.catch methods

  fetch(params.url, {
    method: 'GET',
    headers: {
      'Accept': 'application/json'
    }
  })
  .then(function (response) {
    wrappedPromise.resolve(response);
  }, function (error) {
    wrappedPromise.reject(error);
  })
  .catch(function (error) {
    wrappedPromise.catch(error);
  });

  var timeoutId = setTimeout(function () {
    // reject on timeout
    wrappedPromise.reject(new Error('Load timeout for resource: ' + params.url)); 
  }, MAX_WAITING_TIME);

  return wrappedPromise.promise
    .then(function(response) {
      clearTimeout(timeoutId);
      return response;
    })
    .then(function(response) {
      if (response.status === 200 || response.status === 0) {
        return Promise.resolve(response)
      } else {
        return Promise.reject(new Error(response.statusText))
      }
    })
    .then(function(response) {
      return response.json();
    });
};

(function poll() {
  getJSON({
    url: 'api.example.com/poll'
  }).then(function(data) {// on success
    poll();
    console.log('JSON parsed successfully!');
    console.log(data);
  }, function(error) {// on reject
    poll();
    console.error('An error occured!');
    console.error(error.message ? error.message : error);
  });
})();