refactor(delayWhen): use subscribeToResult with outerSubscriber

src/operator/delayWhen.ts

@@ -3,6 +3,10 @@ import {Subscriber} from '../Subscriber';
 import {Observable} from '../Observable';
 import {Subscription} from '../Subscription';
 
+import {OuterSubscriber} from '../OuterSubscriber';
+import {InnerSubscriber} from '../InnerSubscriber';
+import {subscribeToResult} from '../util/subscribeToResult';
+
 /**
  * Returns an Observable that delays the emission of items from the source Observable
  * by a subscription delay and a delay selector function for each element.
@@ -29,31 +33,41 @@ class DelayWhenOperator<T> implements Operator<T, T> {
   }
 }
 
-class DelayWhenSubscriber<T> extends Subscriber<T> {
+class DelayWhenSubscriber<T, R> extends OuterSubscriber<T, R> {
   private completed: boolean = false;
   private delayNotifierSubscriptions: Array<Subscription> = [];
+  private values: Array<T> = [];
 
   constructor(destination: Subscriber<T>,
               private delayDurationSelector: (value: T) => Observable<any>) {
     super(destination);
   }
 
-  notifyNext(value: T, subscription: Subscription): void {
-    this.destination.next(value);
+  notifyNext(outerValue: T, innerValue: any,
+             outerIndex: number, innerIndex: number,
+             innerSub: InnerSubscriber<T, R>): void {
+    this.destination.next(outerValue);
+    this.removeSubscription(innerSub);
+    this.tryComplete();
+  }
 
-    const subscriptionIdx = this.delayNotifierSubscriptions.indexOf(subscription);
-    if (subscriptionIdx !== -1) {
-      this.delayNotifierSubscriptions.splice(subscriptionIdx, 1);
-    }
+  notifyError(error: any, innerSub: InnerSubscriber<T, R>): void {
+    this._error(error);
+  }
 
+  notifyComplete(innerSub: InnerSubscriber<T, R>): void {
+    const value = this.removeSubscription(innerSub);
+    if (value) {
+      this.destination.next(value);
+    }
     this.tryComplete();
   }
 
   protected _next(value: T): void {
     try {
       const delayNotifier = this.delayDurationSelector(value);
       if (delayNotifier) {
-        this._tryNext(delayNotifier, value);
+        this.tryDelay(delayNotifier, value);
       }
     } catch (err) {
         this.destination.error(err);
@@ -65,41 +79,32 @@ class DelayWhenSubscriber<T> extends Subscriber<T> {
     this.tryComplete();
   }
 
-  private _tryNext(delayNotifier: Observable<any>, value: T): void {
-    const notifierSubscription = new Subscription();
-    notifierSubscription.add(delayNotifier.subscribe(new DelayNotifierSubscriber(this, value, notifierSubscription)));
-    this.add(notifierSubscription);
-    this.delayNotifierSubscriptions.push(notifierSubscription);
-  }
+  private removeSubscription(subscription: InnerSubscriber<T, R>): T {
+    subscription.unsubscribe();
 
-  private tryComplete(): void {
-    if (this.completed && this.delayNotifierSubscriptions.length === 0) {
-      this.destination.complete();
-    }
-  }
-}
+    const subscriptionIdx = this.delayNotifierSubscriptions.indexOf(subscription);
+    let value: T = null;
 
-class DelayNotifierSubscriber<T> extends Subscriber<T> {
-  constructor(private parent: DelayWhenSubscriber<T>, private value: T, private subscription: Subscription) {
-    super();
-  }
+    if (subscriptionIdx !== -1) {
+      value = this.values[subscriptionIdx];
+      this.delayNotifierSubscriptions.splice(subscriptionIdx, 1);
+      this.values.splice(subscriptionIdx, 1);
+    }
 
-  protected _next(unused: any) {
-    this.emitValue();
+    return value;
   }
 
-  protected _error(err: any) {
-    this.parent.error(err);
-  }
+  private tryDelay(delayNotifier: Observable<any>, value: T): void {
+    const notifierSubscription = subscribeToResult(this, delayNotifier, value);
+    this.add(notifierSubscription);
 
-  protected _complete() {
-    this.emitValue();
+    this.delayNotifierSubscriptions.push(notifierSubscription);
+    this.values.push(value);
   }
 
-  private emitValue(): void {
-    if (!this.isUnsubscribed) {
-      this.unsubscribe();
-      this.parent.notifyNext(this.value, this.subscription);
+  private tryComplete(): void {
+    if (this.completed && this.delayNotifierSubscriptions.length === 0) {
+      this.destination.complete();
     }
   }
 }