ZipTeamPurple-FrontEnd/node_modules/sw-toolbox/lib/strategies/fastest.js

/*
  Copyright 2014 Google Inc. All Rights Reserved.

  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
'use strict';
var helpers = require('../helpers');
var cacheOnly = require('./cacheOnly');

function fastest(request, values, options) {
  helpers.debug('Strategy: fastest [' + request.url + ']', options);

  return new Promise(function(resolve, reject) {
    var rejected = false;
    var reasons = [];

    var maybeReject = function(reason) {
      reasons.push(reason.toString());
      if (rejected) {
        reject(new Error('Both cache and network failed: "' +
            reasons.join('", "') + '"'));
      } else {
        rejected = true;
      }
    };

    var maybeResolve = function(result) {
      if (result instanceof Response) {
        resolve(result);
      } else {
        maybeReject('No result returned');
      }
    };

    helpers.fetchAndCache(request.clone(), options)
      .then(maybeResolve, maybeReject);

    cacheOnly(request, values, options)
      .then(maybeResolve, maybeReject);
  });
}

module.exports = fastest;