From 60e7521196bc6fb14d5d0280e1c7163dfc2333ac Mon Sep 17 00:00:00 2001
From: Michal Skvely <michal.sedlak@ubnt.com>
Date: Sun, 29 Apr 2018 13:29:02 +0200
Subject: [PATCH 1/2] test(delay): failing test

---
 spec/operators/delay-spec.ts | 38 +++++++++++++++++++++++++++++++++---
 1 file changed, 35 insertions(+), 3 deletions(-)

diff --git a/spec/operators/delay-spec.ts b/spec/operators/delay-spec.ts
index 83d2b7e769..67777b9a9f 100644
--- a/spec/operators/delay-spec.ts
+++ b/spec/operators/delay-spec.ts
@@ -1,9 +1,12 @@
-import * as Rx from 'rxjs/Rx';
+import { Observable, timer } from 'rxjs';
+import { delay, repeatWhen, skip, take, tap, finalize } from 'rxjs/operators';
+import { TestScheduler } from 'rxjs/testing';
+import * as sinon from 'sinon';
+import { expect } from 'chai';
 import { hot, cold, expectObservable, expectSubscriptions, time } from '../helpers/marble-testing';
 
 declare const asDiagram: Function;
-declare const rxTestScheduler: Rx.TestScheduler;
-const Observable = Rx.Observable;
+declare const rxTestScheduler: TestScheduler;
 
 /** @test {delay} */
 describe('Observable.prototype.delay', () => {
@@ -143,4 +146,33 @@ describe('Observable.prototype.delay', () => {
 
     expectObservable(result).toBe(expected);
   });
+
+  it('should unsubscribe scheduled action when result is unsubscribed explicitly', () => {
+    let subscribeSpy: any = null;
+    const counts: number[] = [];
+
+    const e1 =       cold('a|');
+    const expected =     '--a-(a|)';
+    const duration = time('-|');
+    const result = e1.pipe(
+      repeatWhen(notifications => {
+        const delayed = notifications.pipe(delay(duration, rxTestScheduler));
+        subscribeSpy = sinon.spy(delayed['source'], 'subscribe');
+        return delayed;
+      }),
+      skip(1),
+      take(2),
+      tap({
+        next() {
+          const [[subscriber]] = subscribeSpy.args;
+          counts.push(subscriber._subscriptions.length);
+        },
+        complete() {
+          expect(counts).to.deep.equal([1, 1]);
+        }
+      })
+    );
+
+    expectObservable(result).toBe(expected);
+  });
 });

From 8afb49277d64e85b95d9125db014a4b062c21de0 Mon Sep 17 00:00:00 2001
From: Michal Skvely <michal.sedlak@ubnt.com>
Date: Sun, 29 Apr 2018 13:29:13 +0200
Subject: [PATCH 2/2] fix(delay): fix memory leak

---
 spec/operators/delay-spec.ts    | 8 ++++----
 src/internal/operators/delay.ts | 1 +
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/spec/operators/delay-spec.ts b/spec/operators/delay-spec.ts
index 67777b9a9f..2a042c31af 100644
--- a/spec/operators/delay-spec.ts
+++ b/spec/operators/delay-spec.ts
@@ -1,5 +1,5 @@
-import { Observable, timer } from 'rxjs';
-import { delay, repeatWhen, skip, take, tap, finalize } from 'rxjs/operators';
+import { Observable } from 'rxjs';
+import { delay, repeatWhen, skip, take, tap } from 'rxjs/operators';
 import { TestScheduler } from 'rxjs/testing';
 import * as sinon from 'sinon';
 import { expect } from 'chai';
@@ -147,12 +147,12 @@ describe('Observable.prototype.delay', () => {
     expectObservable(result).toBe(expected);
   });
 
-  it('should unsubscribe scheduled action when result is unsubscribed explicitly', () => {
+  it('should unsubscribe scheduled actions after execution', () => {
     let subscribeSpy: any = null;
     const counts: number[] = [];
 
     const e1 =       cold('a|');
-    const expected =     '--a-(a|)';
+    const expected =      '--a-(a|)';
     const duration = time('-|');
     const result = e1.pipe(
       repeatWhen(notifications => {
diff --git a/src/internal/operators/delay.ts b/src/internal/operators/delay.ts
index 0f786e759a..bd0586f23e 100644
--- a/src/internal/operators/delay.ts
+++ b/src/internal/operators/delay.ts
@@ -92,6 +92,7 @@ class DelaySubscriber<T> extends Subscriber<T> {
       const delay = Math.max(0, queue[0].time - scheduler.now());
       this.schedule(state, delay);
     } else {
+      this.unsubscribe();
       source.active = false;
     }
   }