asapScheduler: Scheduling inside of an executing action only works once

[benlesh]

Originally reported here: #6747 (comment)

Failing test:

  it('scheduling inside of an executing action more than once should work', (done) => {
    const results: any[] = [];

    asapScheduler.schedule(() => {
      results.push(1)
      asapScheduler.schedule(() => results.push(2));
      asapScheduler.schedule(() => results.push(3));
    });

    setTimeout(() => {
      // This should always fire after two recursively scheduled microtasks.
      expect(results).to.deep.equal([1, 2, 3]);
      done() 
    })
  })

[Dedicatus546]

it seems that animateFrameScheduler has the same problem, its source code is similar to asapScheduler , but when i execute the follow code:

animationFrameScheduler.schedule(() => {
  results.push(1);
  animationFrameScheduler.schedule(() => results.push(2));
  animationFrameScheduler.schedule(() => results.push(3));
  animationFrameScheduler.schedule(() => results.push(4));
  animationFrameScheduler.schedule(() => results.push(5));
});

it can't get the results with [1, 2, 3, 4, 5]

but the native method is work well.

is it a bug ?

[Blafasel3]

it seems that animateFrameScheduler has the same problem, its source code is similar to asapScheduler , but when i execute the follow code:

animationFrameScheduler.schedule(() => {
  results.push(1);
  animationFrameScheduler.schedule(() => results.push(2));
  animationFrameScheduler.schedule(() => results.push(3));
  animationFrameScheduler.schedule(() => results.push(4));
  animationFrameScheduler.schedule(() => results.push(5));
});

it can't get the results with [1, 2, 3, 4, 5]

but the native method is work well.

is it a bug ?

It seems our team ran into this issue regarding the animationFrameScheduler as well. We are using the ng-scrollbar library and when scrolling to an particular element, it just happens sometimes that the callback scheduled in the following line https://github.com/MurhafSousli/ngx-scrollbar/blob/master/projects/ngx-scrollbar/smooth-scroll/src/smooth-scroll-manager.ts#L136 is never executed. It just seems to die and only hard refreshing (CTRL+F5) the page actually fixes the issue.