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.exception);
};

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);
  }
};