text: /**
   *
   * Copyright 2018 iQIYI.com
   *
   * 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.
   *
   */
  
  
  var NativePromise = Promise;
  var nativePromiseSupported =
    NativePromise &&
    // Some of these methods are missing from
    // Firefox/Chrome experimental implementations
    'resolve' in NativePromise &&
    'reject' in NativePromise &&
    'all' in NativePromise &&
    'race' in NativePromise &&
    // Older version of the spec had a resolver object
    // as the arg rather than a function
    (function(){
      var resolve;
      new NativePromise(function(r){ resolve = r; });
      return typeof resolve === 'function';
    })();
  
  //
  // Polyfill
  //
  
  var PENDING = 'pending';
  var SEALED = 'sealed';
  var FULFILLED = 'fulfilled';
  var REJECTED = 'rejected';
  var NOOP = function(){};
  
  function isArray(value) {
    return Object.prototype.toString.call(value) === '[object Array]';
  }
  
  // async calls
  var asyncSetTimer = typeof setImmediate !== 'undefined' ? setImmediate : setTimeout;
  var asyncQueue = [];
  var asyncTimer;
  
  function asyncFlush(){
    // run promise callbacks
    for (var i = 0; i < asyncQueue.length; i++){
      asyncQueue[i][0](asyncQueue[i][1]);
  
    }
  
    // reset async asyncQueue
    asyncQueue = [];
    asyncTimer = false;
  }
  
  function asyncCall(callback, arg){
    asyncQueue.push([callback, arg]);
  
    if (!asyncTimer)
    {
      asyncTimer = true;
      asyncSetTimer(asyncFlush, 0);
    }
  }
  
  
  function invokeResolver(resolver, promise) {
    function resolvePromise(value) {
      resolve(promise, value);
    }
  
    function rejectPromise(reason) {
      reject(promise, reason);
    }
  
    try {
      resolver(resolvePromise, rejectPromise);
    } catch(e) {
      rejectPromise(e);
    }
  }
  
  function invokeCallback(subscriber){
    var owner = subscriber.owner;
    var settled = owner.state_;
    var value = owner.data_;  
    var callback = subscriber[settled];
    var promise = subscriber.then;
  
    if (typeof callback === 'function')
    {
      settled = FULFILLED;
      try {
        value = callback(value);
      } catch(e) {
        reject(promise, e);
      }
    }
  
    if (!handleThenable(promise, value))
    {
      if (settled === FULFILLED)
        resolve(promise, value);
  
      if (settled === REJECTED)
        reject(promise, value);
    }
  }
  
  function handleThenable(promise, value) {
    var resolved;
  
    try {
      if (promise === value)
        throw new TypeError('A promises callback cannot return that same promise.');
  
      if (value && (typeof value === 'function' || typeof value === 'object'))
      {
        var then = value.then;  // then should be retrived only once
  
        if (typeof then === 'function')
        {
          then.call(value, function(val){
            if (!resolved)
            {
              resolved = true;
  
              if (value !== val)
                resolve(promise, val);
              else
                fulfill(promise, val);
            }
          }, function(reason){
            if (!resolved)
            {
              resolved = true;
  
              reject(promise, reason);
            }
          });
  
          return true;
        }
      }
    } catch (e) {
      if (!resolved)
        reject(promise, e);
  
      return true;
    }
  
    return false;
  }
  
  function resolve(promise, value){
    if (promise === value || !handleThenable(promise, value))
      fulfill(promise, value);
  }
  
  function fulfill(promise, value){
    if (promise.state_ === PENDING)
    {
      promise.state_ = SEALED;
      promise.data_ = value;
  
      asyncCall(publishFulfillment, promise);
    }
  }
  
  function reject(promise, reason){
    if (promise.state_ === PENDING)
    {
      promise.state_ = SEALED;
      promise.data_ = reason;
  
      asyncCall(publishRejection, promise);
    }
  }
  
  function publish(promise) {
    var callbacks = promise.then_;
    promise.then_ = undefined;
  
    for (var i = 0; i < callbacks.length; i++) {
      invokeCallback(callbacks[i]);
    }
  }
  
  function publishFulfillment(promise){
    promise.state_ = FULFILLED;
    publish(promise);
  }
  
  function publishRejection(promise){
    promise.state_ = REJECTED;
    publish(promise);
  }
  
  /**
  * @class
  */
  function Promise(resolver){
    if (typeof resolver !== 'function')
      throw new TypeError('Promise constructor takes a function argument');
  
    if (this instanceof Promise === false)
      throw new TypeError('Failed to construct \'Promise\': Please use the \'new\' operator, this object constructor cannot be called as a function.');
  
    this.then_ = [];
  
    invokeResolver(resolver, this);
  }
  
  Promise.prototype = {
    constructor: Promise,
  
    state_: PENDING,
    then_: null,
    data_: undefined,
  
    then: function(onFulfillment, onRejection){
      var subscriber = {
        owner: this,
        then: new this.constructor(NOOP),
        fulfilled: onFulfillment,
        rejected: onRejection
      };
  
      if (this.state_ === FULFILLED || this.state_ === REJECTED)
      {
        // already resolved, call callback async
        asyncCall(invokeCallback, subscriber);
      }
      else
      {
        // subscribe
        this.then_.push(subscriber);
      }
  
      return subscriber.then;
    },
  
    'catch': function(onRejection) {
      return this.then(null, onRejection);
    }
  };
  
  Promise.all = function(promises){
    var Class = this;
  
    if (!isArray(promises))
      throw new TypeError('You must pass an array to Promise.all().');
  
    return new Class(function(resolve, reject){
      var results = [];
      var remaining = 0;
  
      function resolver(index){
        remaining++;
        return function(value){
          results[index] = value;
          if (!--remaining)
            resolve(results);
        };
      }
  
      for (var i = 0, promise; i < promises.length; i++)
      {
        promise = promises[i];
  
        if (promise && typeof promise.then === 'function')
          promise.then(resolver(i), reject);
        else
          results[i] = promise;
      }
  
      if (!remaining)
        resolve(results);
    });
  };
  
  Promise.race = function(promises){
    var Class = this;
  
    if (!isArray(promises))
      throw new TypeError('You must pass an array to Promise.race().');
  
    return new Class(function(resolve, reject) {
      for (var i = 0, promise; i < promises.length; i++)
      {
        promise = promises[i];
  
        if (promise && typeof promise.then === 'function')
          promise.then(resolve, reject);
        else
          resolve(promise);
      }
    });
  };
  
  Promise.resolve = function(value){
    var Class = this;
  
    if (value && typeof value === 'object' && value.constructor === Class)
      return value;
  
    return new Class(function(resolve){
      resolve(value);
    });
  };
  
  Promise.reject = function(reason){
    var Class = this;
  
    return new Class(function(resolve, reject){
      reject(reason);
    });
  };
  
  export default nativePromiseSupported ? NativePromise : Promise;
  
  