hunk.code_window:     const e1 = hot('--a-b---a------d----');
       expect(e1.partition).to.throw();
     });
   });
  
hunk.labels: keep keep add keep
hunk.after_edit:   it('should accept thisArg', () => {
       const thisArg = {};
       Observable.of(1).partition(function (value: number) {
         expect(this).to.deep.equal(thisArg);
         return true;
       }, thisArg)
         .forEach((observable: Rx.Observable<number>) => observable.subscribe());
     });
  
hunk.file_path: spec/operators/partition-spec.ts
hunk.type: add
file: import { Observable, ObservableInput } from '../Observable';
  import { ArrayObservable } from '../observable/ArrayObservable';
  import { isArray } from '../util/isArray';
  import { Operator } from '../Operator';
  import { Subscriber } from '../Subscriber';
  import { OuterSubscriber } from '../OuterSubscriber';
  import { InnerSubscriber } from '../InnerSubscriber';
  import { subscribeToResult } from '../util/subscribeToResult';
  const none = {};
  
  /* tslint:disable:max-line-length */
  export function combineLatest<T, R>(this: Observable<T>, project: (v1: T) => R): Observable<R>;
  export function combineLatest<T, T2, R>(this: Observable<T>, v2: ObservableInput<T2>, project: (v1: T, v2: T2) => R): Observable<R>;
  export function combineLatest<T, T2, T3, R>(this: Observable<T>, v2: ObservableInput<T2>, v3: ObservableInput<T3>, project: (v1: T, v2: T2, v3: T3) => R): Observable<R>;
  export function combineLatest<T, T2, T3, T4, R>(this: Observable<T>, v2: ObservableInput<T2>, v3: ObservableInput<T3>, v4: ObservableInput<T4>, project: (v1: T, v2: T2, v3: T3, v4: T4) => R): Observable<R>;
  export function combineLatest<T, T2, T3, T4, T5, R>(this: Observable<T>, v2: ObservableInput<T2>, v3: ObservableInput<T3>, v4: ObservableInput<T4>, v5: ObservableInput<T5>, project: (v1: T, v2: T2, v3: T3, v4: T4, v5: T5) => R): Observable<R>;
  export function combineLatest<T, T2, T3, T4, T5, T6, R>(this: Observable<T>, v2: ObservableInput<T2>, v3: ObservableInput<T3>, v4: ObservableInput<T4>, v5: ObservableInput<T5>, v6: ObservableInput<T6>, project: (v1: T, v2: T2, v3: T3, v4: T4, v5: T5, v6: T6) => R): Observable<R> ;
  export function combineLatest<T, T2>(this: Observable<T>, v2: ObservableInput<T2>): Observable<[T, T2]>;
  export function combineLatest<T, T2, T3>(this: Observable<T>, v2: ObservableInput<T2>, v3: ObservableInput<T3>): Observable<[T, T2, T3]>;
  export function combineLatest<T, T2, T3, T4>(this: Observable<T>, v2: ObservableInput<T2>, v3: ObservableInput<T3>, v4: ObservableInput<T4>): Observable<[T, T2, T3, T4]>;
  export function combineLatest<T, T2, T3, T4, T5>(this: Observable<T>, v2: ObservableInput<T2>, v3: ObservableInput<T3>, v4: ObservableInput<T4>, v5: ObservableInput<T5>): Observable<[T, T2, T3, T4, T5]>;
  export function combineLatest<T, T2, T3, T4, T5, T6>(this: Observable<T>, v2: ObservableInput<T2>, v3: ObservableInput<T3>, v4: ObservableInput<T4>, v5: ObservableInput<T5>, v6: ObservableInput<T6>): Observable<[T, T2, T3, T4, T5, T6]> ;
  export function combineLatest<T, R>(this: Observable<T>, ...observables: Array<ObservableInput<T> | ((...values: Array<T>) => R)>): Observable<R>;
  export function combineLatest<T, R>(this: Observable<T>, array: ObservableInput<T>[]): Observable<Array<T>>;
  export function combineLatest<T, TOther, R>(this: Observable<T>, array: ObservableInput<TOther>[], project: (v1: T, ...values: Array<TOther>) => R): Observable<R>;
  /* tslint:disable:max-line-length */
  
  /**
   * Combines multiple Observables to create an Observable whose values are
   * calculated from the latest values of each of its input Observables.
   *
   * <span class="informal">Whenever any input Observable emits a value, it
   * computes a formula using the latest values from all the inputs, then emits
   * the output of that formula.</span>
   *
   * <img src="./img/combineLatest.png" width="100%">
   *
   * `combineLatest` combines the values from this Observable with values from
   * Observables passed as arguments. This is done by subscribing to each
   * Observable, in order, and collecting an array of each of the most recent
   * values any time any of the input Observables emits, then either taking that
   * array and passing it as arguments to an optional `project` function and
   * emitting the return value of that, or just emitting the array of recent
   * values directly if there is no `project` function.
   *
   * @example <caption>Dynamically calculate the Body-Mass Index from an Observable of weight and one for height</caption>
   * var weight = Rx.Observable.of(70, 72, 76, 79, 75);
   * var height = Rx.Observable.of(1.76, 1.77, 1.78);
   * var bmi = weight.combineLatest(height, (w, h) => w / (h * h));
   * bmi.subscribe(x => console.log('BMI is ' + x));
   *
   * @see {@link combineAll}
   * @see {@link merge}
   * @see {@link withLatestFrom}
   *
   * @param {Observable} other An input Observable to combine with the source
   * Observable. More than one input Observables may be given as argument.
   * @param {function} [project] An optional function to project the values from
   * the combined latest values into a new value on the output Observable.
   * @return {Observable} An Observable of projected values from the most recent
   * values from each input Observable, or an array of the most recent values from
   * each input Observable.
   * @method combineLatest
   * @owner Observable
   */
  export function combineLatest<T, R>(this: Observable<T>, ...observables: Array<ObservableInput<any> |
                                                         Array<ObservableInput<any>> |
                                                         ((...values: Array<any>) => R)>): Observable<R> {
    let project: (...values: Array<any>) => R = null;
    if (typeof observables[observables.length - 1] === 'function') {
      project = <(...values: Array<any>) => R>observables.pop();
    }
  
    // if the first and only other argument besides the resultSelector is an array
    // assume it's been called with `combineLatest([obs1, obs2, obs3], project)`
    if (observables.length === 1 && isArray(observables[0])) {
      observables = <any>observables[0];
    }
  
    observables.unshift(this);
  
    return this.lift.call(new ArrayObservable(observables), new CombineLatestOperator(project));
  }
  
  export class CombineLatestOperator<T, R> implements Operator<T, R> {
    constructor(private project?: (...values: Array<any>) => R) {
    }
  
    call(subscriber: Subscriber<R>, source: any): any {
      return source._subscribe(new CombineLatestSubscriber(subscriber, this.project));
    }
  }
  
  /**
   * We need this JSDoc comment for affecting ESDoc.
   * @ignore
   * @extends {Ignored}
   */
  export class CombineLatestSubscriber<T, R> extends OuterSubscriber<T, R> {
    private active: number = 0;
    private values: any[] = [];
    private observables: any[] = [];
    private toRespond: number;
  
    constructor(destination: Subscriber<R>, private project?: (...values: Array<any>) => R) {
      super(destination);
    }
  
    protected _next(observable: any) {
      this.values.push(none);
      this.observables.push(observable);
    }
  
    protected _complete() {
      const observables = this.observables;
      const len = observables.length;
      if (len === 0) {
        this.destination.complete();
      } else {
        this.active = len;
        this.toRespond = len;
        for (let i = 0; i < len; i++) {
          const observable = observables[i];
          this.add(subscribeToResult(this, observable, observable, i));
        }
      }
    }
  
    notifyComplete(unused: Subscriber<R>): void {
      if ((this.active -= 1) === 0) {
        this.destination.complete();
      }
    }
  
    notifyNext(outerValue: T, innerValue: R,
               outerIndex: number, innerIndex: number,
               innerSub: InnerSubscriber<T, R>): void {
      const values = this.values;
      const oldVal = values[outerIndex];
      const toRespond = !this.toRespond
        ? 0
        : oldVal === none ? --this.toRespond : this.toRespond;
      values[outerIndex] = innerValue;
  
      if (toRespond === 0) {
        if (this.project) {
          this._tryProject(values);
        } else {
          this.destination.next(values.slice());
        }
      }
    }
  
    private _tryProject(values: any[]) {
      let result: any;
      try {
        result = this.project.apply(this, values);
      } catch (err) {
        this.destination.error(err);
        return;
      }
      this.destination.next(result);
    }
  }
  