Updated remoting.xhr API to use promises. Removed access to the native

remoting/webapp/unittests/spy_promise.js

-// Copyright 2015 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-'use strict';
-
-/** @suppress {duplicate} */
-var base = base || {};
-
-(function() {
-/**
- * A wrapper around a Promise object that keeps track of all
- * outstanding promises.  This function is written to serve as a
- * drop-in replacement for the native Promise constructor.  To create
- * a SpyPromise from an existing native Promise, use
- * SpyPromise.resolve.
- *
- * Note that this is a pseudo-constructor that actually returns a
- * regular promise with appropriate handlers attached.  This detail
- * should be transparent when SpyPromise.activate has been called.
- *
- * The normal way to use this class is within a call to
- * SpyPromise.run, for example:
- *
- *   base.SpyPromise.run(function() {
- *     myCodeThatUsesPromises();
- *   });
- *   base.SpyPromise.settleAll().then(function() {
- *     console.log('All promises have been settled!');
- *   });
- *
- * @constructor
- * @extends {Promise}
- * @param {function(function(?):?, function(*):?):?} func A function
- *     of the same type used as an argument to the native Promise
- *     constructor, in other words, a function which is called
- *     immediately, and whose arguments are a resolve function and a
- *     reject function.
- */
-base.SpyPromise = function(func) {
-  var unsettled = new RealPromise(func);
-  var unsettledId = remember(unsettled);
-  return unsettled.then(function(/** * */value) {
-    forget(unsettledId);
-    return value;
-  }, function(error) {
-    forget(unsettledId);
-    throw error;
-  });
-};
-
-/**
- * The real promise constructor.  Needed because it is normally hidden
- * by SpyPromise.activate or SpyPromise.run.
- * @const
- */
-var RealPromise = Promise;
-
-/**
- * The real window.setTimeout method.  Needed because some test
- * frameworks like to replace this method with a fake implementation.
- * @const
- */
-var realSetTimeout = window.setTimeout.bind(window);
-
-/**
- * The number of unsettled promises.
- * @type {number}
- */
-base.SpyPromise.unsettledCount;  // initialized by reset()
-
-/**
- * A collection of all unsettled promises.
- * @type {!Object<number,!Promise>}
- */
-var unsettled;  // initialized by reset()
-
-/**
- * A counter used to assign ID numbers to new SpyPromise objects.
- * @type {number}
- */
-var nextPromiseId;  // initialized by reset()
-
-/**
- * A promise returned by SpyPromise.settleAll.
- * @type {Promise<null>}
- */
-var settleAllPromise;  // initialized by reset()
-
-/**
- * Records an unsettled promise.
- *
- * @param {!Promise} unsettledPromise
- * @return {number} The ID number to be passed to forget_.
- */
-function remember(unsettledPromise) {
-  var id = nextPromiseId++;
-  if (unsettled[id] != null) {
-    throw Error('Duplicate ID: ' + id);
-  }
-  base.SpyPromise.unsettledCount++;
-  unsettled[id] = unsettledPromise;
-  return id;
-};
-
-/**
- * Forgets a promise.  Called after the promise has been settled.
- *
- * @param {number} id
- * @private
- */
-function forget(id) {
-  base.debug.assert(unsettled[id] != null);
-  base.SpyPromise.unsettledCount--;
-  delete unsettled[id];
-};
-
-/**
- * Forgets about all unsettled promises.
- */
-base.SpyPromise.reset = function() {
-  base.SpyPromise.unsettledCount = 0;
-  unsettled = {};
-  nextPromiseId = 0;
-  settleAllPromise = null;
-};
-
-// Initialize static variables.
-base.SpyPromise.reset();
-
-/**
- * Tries to wait until all promises has been settled.
- *
- * @param {number=} opt_maxTimeMs The maximum number of milliseconds
- *     (approximately) to wait (default: 1000).
- * @return {!Promise<null>} A real promise that is resolved when all
- *     SpyPromises have been settled, or rejected after opt_maxTimeMs
- *     milliseconds have elapsed.
- */
-base.SpyPromise.settleAll = function(opt_maxTimeMs) {
-  if (settleAllPromise) {
-    return settleAllPromise;
-  }
-
-  var maxDelay = opt_maxTimeMs == null ? 1000 : opt_maxTimeMs;
-
-  /**
-   * @param {number} count
-   * @param {number} totalDelay
-   * @return {!Promise<null>}
-   */
-  function loop(count, totalDelay) {
-    return new RealPromise(function(resolve, reject) {
-      if (base.SpyPromise.unsettledCount == 0) {
-        settleAllPromise = null;
-        resolve(null);
-      } else if (totalDelay > maxDelay) {
-        settleAllPromise = null;
-        base.SpyPromise.reset();
-        reject(new Error('base.SpyPromise.settleAll timed out'));
-      } else {
-        // This implements quadratic backoff according to Euler's
-        // triangular number formula.
-        var delay = count;
-
-        // Must jump through crazy hoops to get a real timer in a unit test.
-        realSetTimeout(function() {
-          resolve(loop(
-              count + 1,
-              delay + totalDelay));
-        }, delay);
-      }
-    });
-  };
-
-  // An extra promise needed here to prevent the loop function from
-  // finishing before settleAllPromise is set.  If that happens,
-  // settleAllPromise will never be reset to null.
-  settleAllPromise = RealPromise.resolve().then(function() {
-    return loop(0, 0);
-  });
-  return settleAllPromise;
-};
-
-/**
- * Only for testing this class.  Do not use.
- * @returns {boolean} True if settleAll is executing.
- */
-base.SpyPromise.isSettleAllRunning = function() {
-  return settleAllPromise != null;
-};
-
-/**
- * Wrapper for Promise.resolve.
- *
- * @param {*} value
- * @return {!base.SpyPromise}
- */
-base.SpyPromise.resolve = function(value) {
-  return new base.SpyPromise(function(resolve, reject) {
-    resolve(value);
-  });
-};
-
-/**
- * Wrapper for Promise.reject.
- *
- * @param {*} value
- * @return {!base.SpyPromise}
- */
-base.SpyPromise.reject = function(value) {
-  return new base.SpyPromise(function(resolve, reject) {
-    reject(value);
-  });
-};
-
-/**
- * Wrapper for Promise.all.
- *
- * @param  {!Array<Promise>} promises
- * @return {!base.SpyPromise}
- */
-base.SpyPromise.all = function(promises) {
-  return base.SpyPromise.resolve(RealPromise.all(promises));
-};
-
-/**
- * Wrapper for Promise.race.
- *
- * @param {!Array<Promise>} promises
- * @return {!base.SpyPromise}
- */
-base.SpyPromise.race = function(promises) {
-  return base.SpyPromise.resolve(RealPromise.race(promises));
-};
-
-/**
- * Sets Promise = base.SpyPromise.  Must not be called more than once
- * without an intervening call to restore().
- */
-base.SpyPromise.activate = function() {
-  if (settleAllPromise) {
-    throw Error('called base.SpyPromise.activate while settleAll is running');
-  }
-  if (Promise === base.SpyPromise) {
-    throw Error('base.SpyPromise is already active');
-  }
-  Promise = base.SpyPromise;
-};
-
-/**
- * Restores the original value of Promise.
- */
-base.SpyPromise.restore = function() {
-  if (settleAllPromise) {
-    throw Error('called base.SpyPromise.restore while settleAll is running');
-  }
-  if (Promise === base.SpyPromise) {
-    Promise = RealPromise;
-  } else if (Promise === RealPromise) {
-    throw new Error('base.SpyPromise is not active.');
-  } else {
-    throw new Error('Something fishy is going on.');
-  }
-};
-
-/**
- * Calls func with Promise equal to base.SpyPromise.
- *
- * @param {function():void} func A function which is expected to
- *     create one or more promises.
- * @param {number=} opt_timeoutMs An optional timeout specifying how
- *     long to wait for promise chains started in func to be settled.
- *     (default: 1000 ms)
- * @return {!Promise<null>} A promise that is resolved after every
- *     promise chain started in func is fully settled, or rejected
- *     after a opt_timeoutMs.  In any case, the original value of the
- *     Promise constructor is restored before this promise is settled.
- */
-base.SpyPromise.run = function(func, opt_timeoutMs) {
-  base.SpyPromise.activate();
-  try {
-    func();
-  } finally {
-    return base.SpyPromise.settleAll(opt_timeoutMs).then(function() {
-      base.SpyPromise.restore();
-      return null;
-    }, function(error) {
-      base.SpyPromise.restore();
-      throw error;
-    });
-  }
-};
-})();