// Copyright (c) Microsoft, All rights reserved. See License.txt in the project root for license information.

;(function (factory) {
  var objectTypes = {
    'function': true,
    'object': true
  };

  function checkGlobal(value) {
    return (value && value.Object === Object) ? value : null;
  }

  var freeExports = (objectTypes[typeof exports] && exports && !exports.nodeType) ? exports : null;
  var freeModule = (objectTypes[typeof module] && module && !module.nodeType) ? module : null;
  var freeGlobal = checkGlobal(freeExports && freeModule && typeof global === 'object' && global);
  var freeSelf = checkGlobal(objectTypes[typeof self] && self);
  var freeWindow = checkGlobal(objectTypes[typeof window] && window);
  var moduleExports = (freeModule && freeModule.exports === freeExports) ? freeExports : null;
  var thisGlobal = checkGlobal(objectTypes[typeof this] && this);
  var root = freeGlobal || ((freeWindow !== (thisGlobal && thisGlobal.window)) && freeWindow) || freeSelf || thisGlobal || Function('return this')();

    // Because of build optimizers
    if (typeof define === 'function' && define.amd) {
        define(['./rx.core'], function (Rx, exports) {
            return factory(root, exports, Rx);
        });
    } else if (typeof module === 'object' && module && module.exports === freeExports) {
        module.exports = factory(root, module.exports, require('./rx.core'));
    } else {
        root.Rx = factory(root, {}, root.Rx);
    }
}.call(this, function (root, exp, Rx, undefined) {

  // Defaults
  var Observer = Rx.Observer,
    Observable = Rx.Observable,
    Disposable = Rx.Disposable,
    disposableEmpty = Disposable.empty,
    disposableCreate = Disposable.create,
    CompositeDisposable = Rx.CompositeDisposable,
    SingleAssignmentDisposable = Rx.SingleAssignmentDisposable,
    Scheduler = Rx.Scheduler,
    ScheduledItem = Rx.internals.ScheduledItem,
    SchedulePeriodicRecursive  = Rx.internals.SchedulePeriodicRecursive,
    PriorityQueue = Rx.internals.PriorityQueue,
    inherits = Rx.internals.inherits,
    notImplemented = Rx.helpers.notImplemented,
    defaultComparer = Rx.helpers.defaultComparer = function (a, b) { return isEqual(a, b); };

  /**
   *  Represents a notification to an observer.
   */
  var Notification = Rx.Notification = (function () {
    function Notification() {

    }

    Notification.prototype._accept = function (onNext, onError, onCompleted) {
      throw new NotImplementedError();
    };

    Notification.prototype._acceptObserver = function (onNext, onError, onCompleted) {
      throw new NotImplementedError();
    };

    /**
     * Invokes the delegate corresponding to the notification or the observer's method corresponding to the notification and returns the produced result.
     * @param {Function | Observer} observerOrOnNext Function to invoke for an OnNext notification or Observer to invoke the notification on..
     * @param {Function} onError Function to invoke for an OnError notification.
     * @param {Function} onCompleted Function to invoke for an OnCompleted notification.
     * @returns {Any} Result produced by the observation.
     */
    Notification.prototype.accept = function (observerOrOnNext, onError, onCompleted) {
      return observerOrOnNext && typeof observerOrOnNext === 'object' ?
        this._acceptObserver(observerOrOnNext) :
        this._accept(observerOrOnNext, onError, onCompleted);
    };

    /**
     * Returns an observable sequence with a single notification.
     *
     * @memberOf Notifications
     * @param {Scheduler} [scheduler] Scheduler to send out the notification calls on.
     * @returns {Observable} The observable sequence that surfaces the behavior of the notification upon subscription.
     */
    Notification.prototype.toObservable = function (scheduler) {
      var self = this;
      isScheduler(scheduler) || (scheduler = immediateScheduler);
      return new AnonymousObservable(function (o) {
        return scheduler.schedule(self, function (_, notification) {
          notification._acceptObserver(o);
          notification.kind === 'N' && o.onCompleted();
        });
      });
    };

    return Notification;
  })();

  var OnNextNotification = (function (__super__) {
    inherits(OnNextNotification, __super__);
    function OnNextNotification(value) {
      this.value = value;
      this.kind = 'N';
    }

    OnNextNotification.prototype._accept = function (onNext) {
      return onNext(this.value);
    };

    OnNextNotification.prototype._acceptObserver = function (o) {
      return o.onNext(this.value);
    };

    OnNextNotification.prototype.toString = function () {
      return 'OnNext(' + this.value + ')';
    };

    return OnNextNotification;
  }(Notification));

  var OnErrorNotification = (function (__super__) {
    inherits(OnErrorNotification, __super__);
    function OnErrorNotification(error) {
      this.error = error;
      this.kind = 'E';
    }

    OnErrorNotification.prototype._accept = function (onNext, onError) {
      return onError(this.error);
    };

    OnErrorNotification.prototype._acceptObserver = function (o) {
      return o.onError(this.error);
    };

    OnErrorNotification.prototype.toString = function () {
      return 'OnError(' + this.error + ')';
    };

    return OnErrorNotification;
  }(Notification));

  var OnCompletedNotification = (function (__super__) {
    inherits(OnCompletedNotification, __super__);
    function OnCompletedNotification() {
      this.kind = 'C';
    }

    OnCompletedNotification.prototype._accept = function (onNext, onError, onCompleted) {
      return onCompleted();
    };

    OnCompletedNotification.prototype._acceptObserver = function (o) {
      return o.onCompleted();
    };

    OnCompletedNotification.prototype.toString = function () {
      return 'OnCompleted()';
    };

    return OnCompletedNotification;
  }(Notification));

  /**
   * Creates an object that represents an OnNext notification to an observer.
   * @param {Any} value The value contained in the notification.
   * @returns {Notification} The OnNext notification containing the value.
   */
  var notificationCreateOnNext = Notification.createOnNext = function (value) {
    return new OnNextNotification(value);
  };

  /**
   * Creates an object that represents an OnError notification to an observer.
   * @param {Any} error The exception contained in the notification.
   * @returns {Notification} The OnError notification containing the exception.
   */
  var notificationCreateOnError = Notification.createOnError = function (error) {
    return new OnErrorNotification(error);
  };

  /**
   * Creates an object that represents an OnCompleted notification to an observer.
   * @returns {Notification} The OnCompleted notification.
   */
  var notificationCreateOnCompleted = Notification.createOnCompleted = function () {
    return new OnCompletedNotification();
  };

  /** Used to determine if values are of the language type Object */
  var dontEnums = ['toString',
    'toLocaleString',
    'valueOf',
    'hasOwnProperty',
    'isPrototypeOf',
    'propertyIsEnumerable',
    'constructor'],
  dontEnumsLength = dontEnums.length;

var argsTag = '[object Arguments]',
    arrayTag = '[object Array]',
    boolTag = '[object Boolean]',
    dateTag = '[object Date]',
    errorTag = '[object Error]',
    funcTag = '[object Function]',
    mapTag = '[object Map]',
    numberTag = '[object Number]',
    objectTag = '[object Object]',
    regexpTag = '[object RegExp]',
    setTag = '[object Set]',
    stringTag = '[object String]',
    weakMapTag = '[object WeakMap]';

var arrayBufferTag = '[object ArrayBuffer]',
    float32Tag = '[object Float32Array]',
    float64Tag = '[object Float64Array]',
    int8Tag = '[object Int8Array]',
    int16Tag = '[object Int16Array]',
    int32Tag = '[object Int32Array]',
    uint8Tag = '[object Uint8Array]',
    uint8ClampedTag = '[object Uint8ClampedArray]',
    uint16Tag = '[object Uint16Array]',
    uint32Tag = '[object Uint32Array]';

var typedArrayTags = {};
typedArrayTags[float32Tag] = typedArrayTags[float64Tag] =
typedArrayTags[int8Tag] = typedArrayTags[int16Tag] =
typedArrayTags[int32Tag] = typedArrayTags[uint8Tag] =
typedArrayTags[uint8ClampedTag] = typedArrayTags[uint16Tag] =
typedArrayTags[uint32Tag] = true;
typedArrayTags[argsTag] = typedArrayTags[arrayTag] =
typedArrayTags[arrayBufferTag] = typedArrayTags[boolTag] =
typedArrayTags[dateTag] = typedArrayTags[errorTag] =
typedArrayTags[funcTag] = typedArrayTags[mapTag] =
typedArrayTags[numberTag] = typedArrayTags[objectTag] =
typedArrayTags[regexpTag] = typedArrayTags[setTag] =
typedArrayTags[stringTag] = typedArrayTags[weakMapTag] = false;

var objectProto = Object.prototype,
    hasOwnProperty = objectProto.hasOwnProperty,
    objToString = objectProto.toString,
    MAX_SAFE_INTEGER = Math.pow(2, 53) - 1;

var keys = Object.keys || (function() {
    var hasOwnProperty = Object.prototype.hasOwnProperty,
        hasDontEnumBug = !({ toString: null }).propertyIsEnumerable('toString'),
        dontEnums = [
          'toString',
          'toLocaleString',
          'valueOf',
          'hasOwnProperty',
          'isPrototypeOf',
          'propertyIsEnumerable',
          'constructor'
        ],
        dontEnumsLength = dontEnums.length;

    return function(obj) {
      if (typeof obj !== 'object' && (typeof obj !== 'function' || obj === null)) {
        throw new TypeError('Object.keys called on non-object');
      }

      var result = [], prop, i;

      for (prop in obj) {
        if (hasOwnProperty.call(obj, prop)) {
          result.push(prop);
        }
      }

      if (hasDontEnumBug) {
        for (i = 0; i < dontEnumsLength; i++) {
          if (hasOwnProperty.call(obj, dontEnums[i])) {
            result.push(dontEnums[i]);
          }
        }
      }
      return result;
    };
  }());

function equalObjects(object, other, equalFunc, isLoose, stackA, stackB) {
  var objProps = keys(object),
      objLength = objProps.length,
      othProps = keys(other),
      othLength = othProps.length;

  if (objLength !== othLength && !isLoose) {
    return false;
  }
  var index = objLength, key;
  while (index--) {
    key = objProps[index];
    if (!(isLoose ? key in other : hasOwnProperty.call(other, key))) {
      return false;
    }
  }
  var skipCtor = isLoose;
  while (++index < objLength) {
    key = objProps[index];
    var objValue = object[key],
        othValue = other[key],
        result;

    if (!(result === undefined ? equalFunc(objValue, othValue, isLoose, stackA, stackB) : result)) {
      return false;
    }
    skipCtor || (skipCtor = key === 'constructor');
  }
  if (!skipCtor) {
    var objCtor = object.constructor,
        othCtor = other.constructor;

    if (objCtor !== othCtor &&
        ('constructor' in object && 'constructor' in other) &&
        !(typeof objCtor === 'function' && objCtor instanceof objCtor &&
          typeof othCtor === 'function' && othCtor instanceof othCtor)) {
      return false;
    }
  }
  return true;
}

function equalByTag(object, other, tag) {
  switch (tag) {
    case boolTag:
    case dateTag:
      return +object === +other;

    case errorTag:
      return object.name === other.name && object.message === other.message;

    case numberTag:
      return (object !== +object) ?
        other !== +other :
        object === +other;

    case regexpTag:
    case stringTag:
      return object === (other + '');
  }
  return false;
}

var isObject = Rx.internals.isObject = function(value) {
  var type = typeof value;
  return !!value && (type === 'object' || type === 'function');
};

function isObjectLike(value) {
  return !!value && typeof value === 'object';
}

function isLength(value) {
  return typeof value === 'number' && value > -1 && value % 1 === 0 && value <= MAX_SAFE_INTEGER;
}

var isHostObject = (function() {
  try {
    Object({ 'toString': 0 } + '');
  } catch(e) {
    return function() { return false; };
  }
  return function(value) {
    return typeof value.toString !== 'function' && typeof (value + '') === 'string';
  };
}());

function isTypedArray(value) {
  return isObjectLike(value) && isLength(value.length) && !!typedArrayTags[objToString.call(value)];
}

var isArray = Array.isArray || function(value) {
  return isObjectLike(value) && isLength(value.length) && objToString.call(value) === arrayTag;
};

function arraySome (array, predicate) {
  var index = -1,
      length = array.length;

  while (++index < length) {
    if (predicate(array[index], index, array)) {
      return true;
    }
  }
  return false;
}

function equalArrays(array, other, equalFunc, isLoose, stackA, stackB) {
  var index = -1,
      arrLength = array.length,
      othLength = other.length;

  if (arrLength !== othLength && !(isLoose && othLength > arrLength)) {
    return false;
  }
  // Ignore non-index properties.
  while (++index < arrLength) {
    var arrValue = array[index],
        othValue = other[index],
        result;

    if (result !== undefined) {
      if (result) {
        continue;
      }
      return false;
    }
    // Recursively compare arrays (susceptible to call stack limits).
    if (isLoose) {
      if (!arraySome(other, function(othValue) {
            return arrValue === othValue || equalFunc(arrValue, othValue, isLoose, stackA, stackB);
          })) {
        return false;
      }
    } else if (!(arrValue === othValue || equalFunc(arrValue, othValue, isLoose, stackA, stackB))) {
      return false;
    }
  }
  return true;
}

function baseIsEqualDeep(object, other, equalFunc, isLoose, stackA, stackB) {
  var objIsArr = isArray(object),
      othIsArr = isArray(other),
      objTag = arrayTag,
      othTag = arrayTag;

  if (!objIsArr) {
    objTag = objToString.call(object);
    if (objTag === argsTag) {
      objTag = objectTag;
    } else if (objTag !== objectTag) {
      objIsArr = isTypedArray(object);
    }
  }
  if (!othIsArr) {
    othTag = objToString.call(other);
    if (othTag === argsTag) {
      othTag = objectTag;
    }
  }
  var objIsObj = objTag === objectTag && !isHostObject(object),
      othIsObj = othTag === objectTag && !isHostObject(other),
      isSameTag = objTag === othTag;

  if (isSameTag && !(objIsArr || objIsObj)) {
    return equalByTag(object, other, objTag);
  }
  if (!isLoose) {
    var objIsWrapped = objIsObj && hasOwnProperty.call(object, '__wrapped__'),
        othIsWrapped = othIsObj && hasOwnProperty.call(other, '__wrapped__');

    if (objIsWrapped || othIsWrapped) {
      return equalFunc(objIsWrapped ? object.value() : object, othIsWrapped ? other.value() : other, isLoose, stackA, stackB);
    }
  }
  if (!isSameTag) {
    return false;
  }
  // Assume cyclic values are equal.
  // For more information on detecting circular references see https://es5.github.io/#JO.
  stackA || (stackA = []);
  stackB || (stackB = []);

  var length = stackA.length;
  while (length--) {
    if (stackA[length] === object) {
      return stackB[length] === other;
    }
  }
  // Add `object` and `other` to the stack of traversed objects.
  stackA.push(object);
  stackB.push(other);

  var result = (objIsArr ? equalArrays : equalObjects)(object, other, equalFunc, isLoose, stackA, stackB);

  stackA.pop();
  stackB.pop();

  return result;
}

function baseIsEqual(value, other, isLoose, stackA, stackB) {
  if (value === other) {
    return true;
  }
  if (value == null || other == null || (!isObject(value) && !isObjectLike(other))) {
    return value !== value && other !== other;
  }
  return baseIsEqualDeep(value, other, baseIsEqual, isLoose, stackA, stackB);
}

var isEqual = Rx.internals.isEqual = function (value, other) {
  return baseIsEqual(value, other);
};

  var SchedulePeriodicRecursive = Rx.internals.SchedulePeriodicRecursive = (function () {
    function createTick(self) {
      return function tick(command, recurse) {
        recurse(0, self._period);
        var state = tryCatch(self._action)(self._state);
        if (state === errorObj) {
          self._cancel.dispose();
          thrower(state.e);
        }
        self._state = state;
      };
    }

    function SchedulePeriodicRecursive(scheduler, state, period, action) {
      this._scheduler = scheduler;
      this._state = state;
      this._period = period;
      this._action = action;
    }

    SchedulePeriodicRecursive.prototype.start = function () {
      var d = new SingleAssignmentDisposable();
      this._cancel = d;
      d.setDisposable(this._scheduler.scheduleRecursiveFuture(0, this._period, createTick(this)));

      return d;
    };

    return SchedulePeriodicRecursive;
  }());

  /** Provides a set of extension methods for virtual time scheduling. */
  var VirtualTimeScheduler = Rx.VirtualTimeScheduler = (function (__super__) {
    inherits(VirtualTimeScheduler, __super__);

    /**
     * Creates a new virtual time scheduler with the specified initial clock value and absolute time comparer.
     *
     * @constructor
     * @param {Number} initialClock Initial value for the clock.
     * @param {Function} comparer Comparer to determine causality of events based on absolute time.
     */
    function VirtualTimeScheduler(initialClock, comparer) {
      this.clock = initialClock;
      this.comparer = comparer;
      this.isEnabled = false;
      this.queue = new PriorityQueue(1024);
      __super__.call(this);
    }

    var VirtualTimeSchedulerPrototype = VirtualTimeScheduler.prototype;

    VirtualTimeSchedulerPrototype.now = function () {
      return this.toAbsoluteTime(this.clock);
    };

    VirtualTimeSchedulerPrototype.schedule = function (state, action) {
      return this.scheduleAbsolute(state, this.clock, action);
    };

    VirtualTimeSchedulerPrototype.scheduleFuture = function (state, dueTime, action) {
      var dt = dueTime instanceof Date ?
        this.toRelativeTime(dueTime - this.now()) :
        this.toRelativeTime(dueTime);

      return this.scheduleRelative(state, dt, action);
    };

    /**
     * Adds a relative time value to an absolute time value.
     * @param {Number} absolute Absolute virtual time value.
     * @param {Number} relative Relative virtual time value to add.
     * @return {Number} Resulting absolute virtual time sum value.
     */
    VirtualTimeSchedulerPrototype.add = notImplemented;

    /**
     * Converts an absolute time to a number
     * @param {Any} The absolute time.
     * @returns {Number} The absolute time in ms
     */
    VirtualTimeSchedulerPrototype.toAbsoluteTime = notImplemented;

    /**
     * Converts the TimeSpan value to a relative virtual time value.
     * @param {Number} timeSpan TimeSpan value to convert.
     * @return {Number} Corresponding relative virtual time value.
     */
    VirtualTimeSchedulerPrototype.toRelativeTime = notImplemented;

    /**
     * Schedules a periodic piece of work by dynamically discovering the scheduler's capabilities. The periodic task will be emulated using recursive scheduling.
     * @param {Mixed} state Initial state passed to the action upon the first iteration.
     * @param {Number} period Period for running the work periodically.
     * @param {Function} action Action to be executed, potentially updating the state.
     * @returns {Disposable} The disposable object used to cancel the scheduled recurring action (best effort).
     */
    VirtualTimeSchedulerPrototype.schedulePeriodic = function (state, period, action) {
      var s = new SchedulePeriodicRecursive(this, state, period, action);
      return s.start();
    };

    /**
     * Schedules an action to be executed after dueTime.
     * @param {Mixed} state State passed to the action to be executed.
     * @param {Number} dueTime Relative time after which to execute the action.
     * @param {Function} action Action to be executed.
     * @returns {Disposable} The disposable object used to cancel the scheduled action (best effort).
     */
    VirtualTimeSchedulerPrototype.scheduleRelative = function (state, dueTime, action) {
      var runAt = this.add(this.clock, dueTime);
      return this.scheduleAbsolute(state, runAt, action);
    };

    /**
     * Starts the virtual time scheduler.
     */
    VirtualTimeSchedulerPrototype.start = function () {
      if (!this.isEnabled) {
        this.isEnabled = true;
        do {
          var next = this.getNext();
          if (next !== null) {
            this.comparer(next.dueTime, this.clock) > 0 && (this.clock = next.dueTime);
            next.invoke();
          } else {
            this.isEnabled = false;
          }
        } while (this.isEnabled);
      }
    };

    /**
     * Stops the virtual time scheduler.
     */
    VirtualTimeSchedulerPrototype.stop = function () {
      this.isEnabled = false;
    };

    /**
     * Advances the scheduler's clock to the specified time, running all work till that point.
     * @param {Number} time Absolute time to advance the scheduler's clock to.
     */
    VirtualTimeSchedulerPrototype.advanceTo = function (time) {
      var dueToClock = this.comparer(this.clock, time);
      if (this.comparer(this.clock, time) > 0) { throw new ArgumentOutOfRangeError(); }
      if (dueToClock === 0) { return; }
      if (!this.isEnabled) {
        this.isEnabled = true;
        do {
          var next = this.getNext();
          if (next !== null && this.comparer(next.dueTime, time) <= 0) {
            this.comparer(next.dueTime, this.clock) > 0 && (this.clock = next.dueTime);
            next.invoke();
          } else {
            this.isEnabled = false;
          }
        } while (this.isEnabled);
        this.clock = time;
      }
    };

    /**
     * Advances the scheduler's clock by the specified relative time, running all work scheduled for that timespan.
     * @param {Number} time Relative time to advance the scheduler's clock by.
     */
    VirtualTimeSchedulerPrototype.advanceBy = function (time) {
      var dt = this.add(this.clock, time),
          dueToClock = this.comparer(this.clock, dt);
      if (dueToClock > 0) { throw new ArgumentOutOfRangeError(); }
      if (dueToClock === 0) {  return; }

      this.advanceTo(dt);
    };

    /**
     * Advances the scheduler's clock by the specified relative time.
     * @param {Number} time Relative time to advance the scheduler's clock by.
     */
    VirtualTimeSchedulerPrototype.sleep = function (time) {
      var dt = this.add(this.clock, time);
      if (this.comparer(this.clock, dt) >= 0) { throw new ArgumentOutOfRangeError(); }

      this.clock = dt;
    };

    /**
     * Gets the next scheduled item to be executed.
     * @returns {ScheduledItem} The next scheduled item.
     */
    VirtualTimeSchedulerPrototype.getNext = function () {
      while (this.queue.length > 0) {
        var next = this.queue.peek();
        if (next.isCancelled()) {
          this.queue.dequeue();
        } else {
          return next;
        }
      }
      return null;
    };

    /**
     * Schedules an action to be executed at dueTime.
     * @param {Mixed} state State passed to the action to be executed.
     * @param {Number} dueTime Absolute time at which to execute the action.
     * @param {Function} action Action to be executed.
     * @returns {Disposable} The disposable object used to cancel the scheduled action (best effort).
     */
    VirtualTimeSchedulerPrototype.scheduleAbsolute = function (state, dueTime, action) {
      var self = this;

      function run(scheduler, state1) {
        self.queue.remove(si);
        return action(scheduler, state1);
      }

      var si = new ScheduledItem(this, state, run, dueTime, this.comparer);
      this.queue.enqueue(si);

      return si.disposable;
    };

    return VirtualTimeScheduler;
  }(Scheduler));

function OnNextPredicate(predicate) {
    this.predicate = predicate;
}

OnNextPredicate.prototype.equals = function (other) {
  if (other === this) { return true; }
  if (other == null) { return false; }
  if (other.kind !== 'N') { return false; }
  return this.predicate(other.value);
};

function OnErrorPredicate(predicate) {
  this.predicate = predicate;
}

OnErrorPredicate.prototype.equals = function (other) {
  if (other === this) { return true; }
  if (other == null) { return false; }
  if (other.kind !== 'E') { return false; }
  return this.predicate(other.error);
};

var ReactiveTest = Rx.ReactiveTest = {
  /** Default virtual time used for creation of observable sequences in unit tests. */
  created: 100,
  /** Default virtual time used to subscribe to observable sequences in unit tests. */
  subscribed: 200,
  /** Default virtual time used to dispose subscriptions in unit tests. */
  disposed: 1000,

  /**
   * Factory method for an OnNext notification record at a given time with a given value or a predicate function.
   *
   * 1 - ReactiveTest.onNext(200, 42);
   * 2 - ReactiveTest.onNext(200, function (x) { return x.length == 2; });
   *
   * @param ticks Recorded virtual time the OnNext notification occurs.
   * @param value Recorded value stored in the OnNext notification or a predicate.
   * @return Recorded OnNext notification.
   */
  onNext: function (ticks, value) {
    return typeof value === 'function' ?
      new Recorded(ticks, new OnNextPredicate(value)) :
      new Recorded(ticks, Notification.createOnNext(value));
  },
  /**
   * Factory method for an OnError notification record at a given time with a given error.
   *
   * 1 - ReactiveTest.onNext(200, new Error('error'));
   * 2 - ReactiveTest.onNext(200, function (e) { return e.message === 'error'; });
   *
   * @param ticks Recorded virtual time the OnError notification occurs.
   * @param exception Recorded exception stored in the OnError notification.
   * @return Recorded OnError notification.
   */
  onError: function (ticks, error) {
    return typeof error === 'function' ?
      new Recorded(ticks, new OnErrorPredicate(error)) :
      new Recorded(ticks, Notification.createOnError(error));
  },
  /**
   * Factory method for an OnCompleted notification record at a given time.
   *
   * @param ticks Recorded virtual time the OnCompleted notification occurs.
   * @return Recorded OnCompleted notification.
   */
  onCompleted: function (ticks) {
    return new Recorded(ticks, Notification.createOnCompleted());
  },
  /**
   * Factory method for a subscription record based on a given subscription and disposal time.
   *
   * @param start Virtual time indicating when the subscription was created.
   * @param end Virtual time indicating when the subscription was disposed.
   * @return Subscription object.
   */
  subscribe: function (start, end) {
    return new Subscription(start, end);
  }
};

  /**
   * Creates a new object recording the production of the specified value at the given virtual time.
   *
   * @constructor
   * @param {Number} time Virtual time the value was produced on.
   * @param {Mixed} value Value that was produced.
   * @param {Function} comparer An optional comparer.
   */
  var Recorded = Rx.Recorded = function (time, value, comparer) {
    this.time = time;
    this.value = value;
    this.comparer = comparer || defaultComparer;
  };

  /**
   * Checks whether the given recorded object is equal to the current instance.
   *
   * @param {Recorded} other Recorded object to check for equality.
   * @returns {Boolean} true if both objects are equal; false otherwise.
   */
  Recorded.prototype.equals = function (other) {
    return this.time === other.time && this.comparer(this.value, other.value);
  };

  /**
   * Returns a string representation of the current Recorded value.
   *
   * @returns {String} String representation of the current Recorded value.
   */
  Recorded.prototype.toString = function () {
    return this.value.toString() + '@' + this.time;
  };

  /**
   * Creates a new subscription object with the given virtual subscription and unsubscription time.
   *
   * @constructor
   * @param {Number} subscribe Virtual time at which the subscription occurred.
   * @param {Number} unsubscribe Virtual time at which the unsubscription occurred.
   */
  var Subscription = Rx.Subscription = function (start, end) {
    this.subscribe = start;
    this.unsubscribe = end || Number.MAX_VALUE;
  };

  /**
   * Checks whether the given subscription is equal to the current instance.
   * @param other Subscription object to check for equality.
   * @returns {Boolean} true if both objects are equal; false otherwise.
   */
  Subscription.prototype.equals = function (other) {
    return this.subscribe === other.subscribe && this.unsubscribe === other.unsubscribe;
  };

  /**
   * Returns a string representation of the current Subscription value.
   * @returns {String} String representation of the current Subscription value.
   */
  Subscription.prototype.toString = function () {
    return '(' + this.subscribe + ', ' + (this.unsubscribe === Number.MAX_VALUE ? 'Infinite' : this.unsubscribe) + ')';
  };

  var MockDisposable = Rx.MockDisposable = function (scheduler) {
    this.scheduler = scheduler;
    this.disposes = [];
    this.disposes.push(this.scheduler.clock);
  };

  MockDisposable.prototype.dispose = function () {
    this.disposes.push(this.scheduler.clock);
  };

  var MockObserver = (function (__super__) {
    inherits(MockObserver, __super__);

    function MockObserver(scheduler) {
      __super__.call(this);
      this.scheduler = scheduler;
      this.messages = [];
    }

    var MockObserverPrototype = MockObserver.prototype;

    MockObserverPrototype.onNext = function (value) {
      this.messages.push(new Recorded(this.scheduler.clock, Notification.createOnNext(value)));
    };

    MockObserverPrototype.onError = function (e) {
      this.messages.push(new Recorded(this.scheduler.clock, Notification.createOnError(e)));
    };

    MockObserverPrototype.onCompleted = function () {
      this.messages.push(new Recorded(this.scheduler.clock, Notification.createOnCompleted()));
    };

    return MockObserver;
  })(Observer);

  function MockPromise(scheduler, messages) {
    var self = this;
    this.scheduler = scheduler;
    this.messages = messages;
    this.subscriptions = [];
    this.observers = [];
    for (var i = 0, len = this.messages.length; i < len; i++) {
      var message = this.messages[i],
          notification = message.value;
      (function (innerNotification) {
        scheduler.scheduleAbsolute(null, message.time, function () {
          var obs = self.observers.slice(0);

          for (var j = 0, jLen = obs.length; j < jLen; j++) {
            innerNotification.accept(obs[j]);
          }
          return disposableEmpty;
        });
      })(notification);
    }
  }

  MockPromise.prototype.then = function (onResolved, onRejected) {
    var self = this;

    this.subscriptions.push(new Subscription(this.scheduler.clock));
    var index = this.subscriptions.length - 1;

    var newPromise;

    var observer = Rx.Observer.create(
      function (x) {
        var retValue = onResolved(x);
        if (retValue && typeof retValue.then === 'function') {
          newPromise = retValue;
        } else {
          var ticks = self.scheduler.clock;
          newPromise = new MockPromise(self.scheduler, [Rx.ReactiveTest.onNext(ticks, undefined), Rx.ReactiveTest.onCompleted(ticks)]);
        }
        var idx = self.observers.indexOf(observer);
        self.observers.splice(idx, 1);
        self.subscriptions[index] = new Subscription(self.subscriptions[index].subscribe, self.scheduler.clock);
      },
      function (err) {
        onRejected(err);
        var idx = self.observers.indexOf(observer);
        self.observers.splice(idx, 1);
        self.subscriptions[index] = new Subscription(self.subscriptions[index].subscribe, self.scheduler.clock);
      }
    );
    this.observers.push(observer);

    return newPromise || new MockPromise(this.scheduler, this.messages);
  };

  var HotObservable = (function (__super__) {
    inherits(HotObservable, __super__);

    function HotObservable(scheduler, messages) {
      __super__.call(this);
      var message, notification, observable = this;
      this.scheduler = scheduler;
      this.messages = messages;
      this.subscriptions = [];
      this.observers = [];
      for (var i = 0, len = this.messages.length; i < len; i++) {
        message = this.messages[i];
        notification = message.value;
        (function (innerNotification) {
          scheduler.scheduleAbsolute(null, message.time, function () {
            var obs = observable.observers.slice(0);

            for (var j = 0, jLen = obs.length; j < jLen; j++) {
              innerNotification.accept(obs[j]);
            }
            return disposableEmpty;
          });
        })(notification);
      }
    }

    HotObservable.prototype._subscribe = function (o) {
      var observable = this;
      this.observers.push(o);
      this.subscriptions.push(new Subscription(this.scheduler.clock));
      var index = this.subscriptions.length - 1;
      return disposableCreate(function () {
        var idx = observable.observers.indexOf(o);
        observable.observers.splice(idx, 1);
        observable.subscriptions[index] = new Subscription(observable.subscriptions[index].subscribe, observable.scheduler.clock);
      });
    };

    return HotObservable;
  })(Observable);

  var ColdObservable = (function (__super__) {
    inherits(ColdObservable, __super__);

    function ColdObservable(scheduler, messages) {
      __super__.call(this);
      this.scheduler = scheduler;
      this.messages = messages;
      this.subscriptions = [];
    }

    ColdObservable.prototype._subscribe = function (o) {
      var message, notification, observable = this;
      this.subscriptions.push(new Subscription(this.scheduler.clock));
      var index = this.subscriptions.length - 1;
      var d = new CompositeDisposable();
      for (var i = 0, len = this.messages.length; i < len; i++) {
        message = this.messages[i];
        notification = message.value;
        (function (innerNotification) {
          d.add(observable.scheduler.scheduleRelative(null, message.time, function () {
            innerNotification.accept(o);
            return disposableEmpty;
          }));
        })(notification);
      }
      return disposableCreate(function () {
        observable.subscriptions[index] = new Subscription(observable.subscriptions[index].subscribe, observable.scheduler.clock);
        d.dispose();
      });
    };

    return ColdObservable;
  })(Observable);

  /** Virtual time scheduler used for testing applications and libraries built using Reactive Extensions. */
  Rx.TestScheduler = (function (__super__) {
    inherits(TestScheduler, __super__);

    function baseComparer(x, y) {
      return x > y ? 1 : (x < y ? -1 : 0);
    }

    function TestScheduler() {
      __super__.call(this, 0, baseComparer);
    }

    /**
     * Schedules an action to be executed at the specified virtual time.
     *
     * @param state State passed to the action to be executed.
     * @param dueTime Absolute virtual time at which to execute the action.
     * @param action Action to be executed.
     * @return Disposable object used to cancel the scheduled action (best effort).
     */
    TestScheduler.prototype.scheduleAbsolute = function (state, dueTime, action) {
      dueTime <= this.clock && (dueTime = this.clock + 1);
      return __super__.prototype.scheduleAbsolute.call(this, state, dueTime, action);
    };
    /**
     * Adds a relative virtual time to an absolute virtual time value.
     *
     * @param absolute Absolute virtual time value.
     * @param relative Relative virtual time value to add.
     * @return Resulting absolute virtual time sum value.
     */
    TestScheduler.prototype.add = function (absolute, relative) {
      return absolute + relative;
    };
    /**
     * Converts the absolute virtual time value to a DateTimeOffset value.
     *
     * @param absolute Absolute virtual time value to convert.
     * @return Corresponding DateTimeOffset value.
     */
    TestScheduler.prototype.toAbsoluteTime = function (absolute) {
      return new Date(absolute).getTime();
    };
    /**
     * Converts the TimeSpan value to a relative virtual time value.
     *
     * @param timeSpan TimeSpan value to convert.
     * @return Corresponding relative virtual time value.
     */
    TestScheduler.prototype.toRelativeTime = function (timeSpan) {
      return timeSpan;
    };
    /**
     * Starts the test scheduler and uses the specified virtual times to invoke the factory function, subscribe to the resulting sequence, and dispose the subscription.
     *
     * @param create Factory method to create an observable sequence.
     * @param created Virtual time at which to invoke the factory to create an observable sequence.
     * @param subscribed Virtual time at which to subscribe to the created observable sequence.
     * @param disposed Virtual time at which to dispose the subscription.
     * @return Observer with timestamped recordings of notification messages that were received during the virtual time window when the subscription to the source sequence was active.
     */
    TestScheduler.prototype.startScheduler = function (createFn, settings) {
      settings || (settings = {});
      settings.created == null && (settings.created = ReactiveTest.created);
      settings.subscribed == null && (settings.subscribed = ReactiveTest.subscribed);
      settings.disposed == null && (settings.disposed = ReactiveTest.disposed);

      var observer = this.createObserver(), source, subscription;

      this.scheduleAbsolute(null, settings.created, function () {
        source = createFn();
        return disposableEmpty;
      });

      this.scheduleAbsolute(null, settings.subscribed, function () {
        subscription = source.subscribe(observer);
        return disposableEmpty;
      });

      this.scheduleAbsolute(null, settings.disposed, function () {
        subscription.dispose();
        return disposableEmpty;
      });

      this.start();

      return observer;
    };

    /**
     * Creates a hot observable using the specified timestamped notification messages either as an array or arguments.
     * @param messages Notifications to surface through the created sequence at their specified absolute virtual times.
     * @return Hot observable sequence that can be used to assert the timing of subscriptions and notifications.
     */
    TestScheduler.prototype.createHotObservable = function () {
      var len = arguments.length, args;
      if (Array.isArray(arguments[0])) {
        args = arguments[0];
      } else {
        args = new Array(len);
        for (var i = 0; i < len; i++) { args[i] = arguments[i]; }
      }
      return new HotObservable(this, args);
    };

    /**
     * Creates a cold observable using the specified timestamped notification messages either as an array or arguments.
     * @param messages Notifications to surface through the created sequence at their specified virtual time offsets from the sequence subscription time.
     * @return Cold observable sequence that can be used to assert the timing of subscriptions and notifications.
     */
    TestScheduler.prototype.createColdObservable = function () {
      var len = arguments.length, args;
      if (Array.isArray(arguments[0])) {
        args = arguments[0];
      } else {
        args = new Array(len);
        for (var i = 0; i < len; i++) { args[i] = arguments[i]; }
      }
      return new ColdObservable(this, args);
    };

    /**
     * Creates a resolved promise with the given value and ticks
     * @param {Number} ticks The absolute time of the resolution.
     * @param {Any} value The value to yield at the given tick.
     * @returns {MockPromise} A mock Promise which fulfills with the given value.
     */
    TestScheduler.prototype.createResolvedPromise = function (ticks, value) {
      return new MockPromise(this, [Rx.ReactiveTest.onNext(ticks, value), Rx.ReactiveTest.onCompleted(ticks)]);
    };

    /**
     * Creates a rejected promise with the given reason and ticks
     * @param {Number} ticks The absolute time of the resolution.
     * @param {Any} reason The reason for rejection to yield at the given tick.
     * @returns {MockPromise} A mock Promise which rejects with the given reason.
     */
    TestScheduler.prototype.createRejectedPromise = function (ticks, reason) {
      return new MockPromise(this, [Rx.ReactiveTest.onError(ticks, reason)]);
    };

    /**
     * Creates an observer that records received notification messages and timestamps those.
     * @return Observer that can be used to assert the timing of received notifications.
     */
    TestScheduler.prototype.createObserver = function () {
      return new MockObserver(this);
    };

    return TestScheduler;
  })(VirtualTimeScheduler);

  return Rx;
}));