message: test: add v8 subscriber-should-stay-closed test
diff: import { expect } from 'chai';
  import { concat, defer, Observable, of, throwError, EMPTY, from } from 'rxjs';
  -import { catchError, map, mergeMap, takeWhile } from 'rxjs/operators';
  +import { catchError, delay, map, mergeMap, takeWhile } from 'rxjs/operators';
  import * as sinon from 'sinon';
  import { createObservableInputs } from '../helpers/test-helper';
  import { TestScheduler } from 'rxjs/testing';
  @@ -430,4 +430,33 @@ describe('catchError operator', () => {
  });
  });
  + // TODO(v8): see https://github.com/ReactiveX/rxjs/issues/5115
  + // The re-implementation in version 8 should fix the problem in the
  + // referenced issue. Closed subscribers should remain closed.
  + /*
  + it('issue #5115', (done: MochaDone) => {
  + const source = new Observable<string>(observer => {
  + observer.error(new Error('kaboom!'));
  + observer.complete();
  + });
  +
  + const sourceWithDelay = new Observable<string>(observer => {
  + observer.next('delayed');
  + observer.complete();
  + }).pipe(delay(0));
  +
  + const values: string[] = [];
  + source.pipe(
  + catchError(err => sourceWithDelay)
  + )
  + .subscribe(
  + value => values.push(value),
  + err => done(err),
  + () => {
  + expect(values).to.deep.equal(['delayed']);
  + done();
  + }
  + );
  + });
  + */
  });
  