fix(audit): fix for ReactiveX#2595 which crashes in case of the durat…

…ion Observable completes

Fixed the problem when subscribeToResult() returns null it will crash described by @deadbeef84.

audit() crashs with Observable.of()

spec/operators/audit-spec.ts

@@ -139,6 +139,18 @@ describe('Observable.prototype.audit', () => {
  expectSubscriptions(e1.subscriptions).toBe(e1subs);
  });
 
+ it('should mirror source if durations are Observable.of()', () => {
+ const e1 = hot('abcdefabcdefabcdefabcdefa|');
+ const e1subs = '^ !';
+ const e2 = Rx.Observable.of('one single value');
+ const expected = 'abcdefabcdefabcdefabcdefa|';
+
+ const result = e1.audit(() => e2);
+
+ expectObservable(result).toBe(expected);
+ expectSubscriptions(e1.subscriptions).toBe(e1subs);
+ });
+
  it('should emit no values if duration is a never', () => {
  const e1 = hot('----abcdefabcdefabcdefabcdefa|');
  const e1subs = '^ !';

src/operator/audit.ts

@@ -86,7 +86,7 @@ class AuditSubscriber<T, R> extends OuterSubscriber<T, R> {
  this.destination.error(errorObject.e);
  } else {
  const innerSubscription = subscribeToResult(this, duration);
- if (innerSubscription.closed) {
+ if (!innerSubscription || innerSubscription.closed) {
  this.clearThrottle();
  } else {
  this.add(this.throttled = innerSubscription);