fix(bufferToggle): accepts closing selector returns promise

relates to ReactiveX#1246
kwonoj · Mar 28, 2016 · df4a03c · df4a03c
1 parent 80b1646
commit df4a03c
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Showing 2 changed files with 89 additions and 50 deletions.
diff --git a/spec/operators/bufferToggle-spec.ts b/spec/operators/bufferToggle-spec.ts
@@ -1,4 +1,5 @@
 import * as Rx from '../../dist/cjs/Rx';
+import {DoneSignature} from '../helpers/test-helper';
 declare const {hot, cold, asDiagram, expectObservable, expectSubscriptions};
 
 const Observable = Rx.Observable;
@@ -341,4 +342,42 @@ describe('Observable.prototype.bufferToggle', () => {
     expectSubscriptions(e1.subscriptions).toBe(e1subs);
     expectSubscriptions(e2.subscriptions).toBe(e2subs);
   });
+
+  it('should accept closing selector that returns a resolved promise', (done: DoneSignature) => {
+    const e1 = Observable.concat(Observable.of(1),
+      Observable.timer(10).mapTo(2),
+      Observable.timer(10).mapTo(3),
+      Observable.timer(100).mapTo(4)
+      );
+    const expected = [[1]];
+
+    e1.bufferToggle(Observable.of(10), () => new Promise((resolve: any) => { resolve(42); }))
+      .subscribe((x) => {
+        expect(x).toEqual(expected.shift()); },
+        done.fail,
+        () => {
+          expect(expected.length).toBe(0);
+          done();
+      });
+  });
+
+  it('should accept closing selector that returns a rejected promise', (done: DoneSignature) => {
+    const e1 = Observable.concat(Observable.of(1),
+      Observable.timer(10).mapTo(2),
+      Observable.timer(10).mapTo(3),
+      Observable.timer(100).mapTo(4)
+      );
+
+    const expected = 42;
+
+    e1.bufferToggle(Observable.of(10), () => new Promise((resolve: any, reject: any) => { reject(expected); }))
+      .subscribe((x) => {
+        done.fail();
+      }, (x) => {
+        expect(x).toBe(expected);
+        done();
+      }, () => {
+        done.fail();
+      });
+  });
 });
diff --git a/src/operator/bufferToggle.ts b/src/operator/bufferToggle.ts
@@ -1,9 +1,11 @@
 import {Operator} from '../Operator';
 import {Subscriber} from '../Subscriber';
-import {Observable} from '../Observable';
+import {Observable, SubscribableOrPromise} from '../Observable';
 import {Subscription} from '../Subscription';
-import {tryCatch} from '../util/tryCatch';
-import {errorObject} from '../util/errorObject';
+
+import {subscribeToResult} from '../util/subscribeToResult';
+import {OuterSubscriber} from '../OuterSubscriber';
+import {InnerSubscriber} from '../InnerSubscriber';
 
 /**
  * Buffers the source Observable values starting from an emission from
@@ -17,7 +19,7 @@ import {errorObject} from '../util/errorObject';
  *
  * Buffers values from the source by opening the buffer via signals from an
  * Observable provided to `openings`, and closing and sending the buffers when
- * an Observable returned by the `closingSelector` function emits.
+ * a Subscribable or Promise returned by the `closingSelector` function emits.
  *
  * @example <caption>Every other second, emit the click events from the next 500ms</caption>
  * var clicks = Rx.Observable.fromEvent(document, 'click');
@@ -36,26 +38,26 @@ import {errorObject} from '../util/errorObject';
  * @param {Observable<O>} openings An observable of notifications to start new
  * buffers.
  * @param {function(value: O): Observable} closingSelector A function that takes
- * the value emitted by the `openings` observable and returns an Observable,
+ * the value emitted by the `openings` observable and returns a Subscribable or Promise,
  * which, when it emits, signals that the associated buffer should be emitted
  * and cleared.
  * @return {Observable<T[]>} An observable of arrays of buffered values.
  * @method bufferToggle
  * @owner Observable
  */
 export function bufferToggle<T, O>(openings: Observable<O>,
-                                   closingSelector: (value: O) => Observable<any>): Observable<T[]> {
+                                   closingSelector: (value: O) => SubscribableOrPromise<any> | void): Observable<T[]> {
   return this.lift(new BufferToggleOperator<T, O>(openings, closingSelector));
 }
 
 export interface BufferToggleSignature<T> {
-  <O>(openings: Observable<O>, closingSelector: (value: O) => Observable<any>): Observable<T[]>;
+  <O>(openings: Observable<O>, closingSelector: (value: O) => SubscribableOrPromise<any> | void): Observable<T[]>;
 }
 
 class BufferToggleOperator<T, O> implements Operator<T, T[]> {
 
   constructor(private openings: Observable<O>,
-              private closingSelector: (value: O) => Observable<any>) {
+              private closingSelector: (value: O) => SubscribableOrPromise<any> | void) {
   }
 
   call(subscriber: Subscriber<T[]>): Subscriber<T> {
@@ -68,25 +70,25 @@ interface BufferContext<T> {
   subscription: Subscription;
 }
 
-class BufferToggleSubscriber<T, O> extends Subscriber<T> {
+class BufferToggleSubscriber<T, O> extends OuterSubscriber<T, O> {
   private contexts: Array<BufferContext<T>> = [];
 
   constructor(destination: Subscriber<T[]>,
               private openings: Observable<O>,
-              private closingSelector: (value: O) => Observable<any>) {
+              private closingSelector: (value: O) => SubscribableOrPromise<any> | void) {
     super(destination);
     this.add(this.openings.subscribe(new BufferToggleOpeningsSubscriber(this)));
   }
 
-  protected _next(value: T) {
+  protected _next(value: T): void {
     const contexts = this.contexts;
     const len = contexts.length;
     for (let i = 0; i < len; i++) {
       contexts[i].buffer.push(value);
     }
   }
 
-  protected _error(err: any) {
+  protected _error(err: any): void {
     const contexts = this.contexts;
     while (contexts.length > 0) {
       const context = contexts.shift();
@@ -98,7 +100,7 @@ class BufferToggleSubscriber<T, O> extends Subscriber<T> {
     super._error(err);
   }
 
-  protected _complete() {
+  protected _complete(): void {
     const contexts = this.contexts;
     while (contexts.length > 0) {
       const context = contexts.shift();
@@ -111,27 +113,29 @@ class BufferToggleSubscriber<T, O> extends Subscriber<T> {
     super._complete();
   }
 
-  openBuffer(value: O) {
-    const closingSelector = this.closingSelector;
-    const contexts = this.contexts;
-
-    let closingNotifier = tryCatch(closingSelector)(value);
-    if (closingNotifier === errorObject) {
-      this._error(errorObject.e);
-    } else {
-      let context = {
-        buffer: <T[]>[],
-        subscription: new Subscription()
-      };
-      contexts.push(context);
-      const subscriber = new BufferToggleClosingsSubscriber<T>(this, context);
-      const subscription = closingNotifier.subscribe(subscriber);
-      context.subscription.add(subscription);
-      this.add(subscription);
+  openBuffer(value: O): void {
+    try {
+      const closingSelector = this.closingSelector;
+      const closingNotifier = closingSelector.call(this, value);
+      if (closingNotifier) {
+        this.trySubscribe(closingNotifier);
+      }
+    } catch (err) {
+      this._error(err);
     }
   }
 
-  closeBuffer(context: BufferContext<T>) {
+  notifyNext(outerValue: any, innerValue: O,
+             outerIndex: number, innerIndex: number,
+             innerSub: InnerSubscriber<T, O>): void {
+    this.closeBuffer(outerValue);
+  }
+
+  notifyComplete(innerSub: InnerSubscriber<T, O>): void {
+    this.closeBuffer((<any> innerSub).context);
+  }
+
+  private closeBuffer(context: BufferContext<T>): void {
     const contexts = this.contexts;
     if (contexts === null) {
       return;
@@ -142,41 +146,37 @@ class BufferToggleSubscriber<T, O> extends Subscriber<T> {
     this.remove(subscription);
     subscription.unsubscribe();
   }
-}
 
-class BufferToggleOpeningsSubscriber<T, O> extends Subscriber<O> {
-  constructor(private parent: BufferToggleSubscriber<T, O>) {
-    super(null);
-  }
+  private trySubscribe(closingNotifier: any): void {
+    const contexts = this.contexts;
 
-  protected _next(value: O) {
-    this.parent.openBuffer(value);
-  }
+    const buffer: Array<T> = [];
+    const subscription = new Subscription();
+    const context = { buffer, subscription };
+    contexts.push(context);
 
-  protected _error(err: any) {
-    this.parent.error(err);
-  }
+    const innerSubscription = subscribeToResult(this, closingNotifier, <any>context);
+    (<any> innerSubscription).context = context;
 
-  protected _complete() {
-    // noop
+    this.add(innerSubscription);
+    subscription.add(innerSubscription);
   }
 }
 
-class BufferToggleClosingsSubscriber<T> extends Subscriber<any> {
-  constructor(private parent: BufferToggleSubscriber<T, any>,
-              private context: { subscription: any, buffer: T[] }) {
+class BufferToggleOpeningsSubscriber<T, O> extends Subscriber<O> {
+  constructor(private parent: BufferToggleSubscriber<T, O>) {
     super(null);
   }
 
-  protected _next() {
-    this.parent.closeBuffer(this.context);
+  protected _next(value: O) {
+    this.parent.openBuffer(value);
   }
 
   protected _error(err: any) {
     this.parent.error(err);
   }
 
   protected _complete() {
-    this.parent.closeBuffer(this.context);
+    // noop
   }
 }