Angular component testing: Asynchronous test fails without sleep #47006-CodePudding

I have a component that allows images uploading, once the user adds an image, it emits an event (the parent should handle it), but doing some unit test over that component I'm not able to pass the test without doing some sleep (wait for event to be triggered).

Test purpose: Validate (spy) the event is emitted

spyOn(component.fileAdded, 'emit');
uploadFiles(element, [new File([''], 'test_file.png')]);
fixture.detectChanges();

expect(component.fileAdded.emit).toHaveBeenCalledWith({
  filePath: jasmine.any(String),
  fileBase64: jasmine.any(String),
});

See reproduction

I tested:

With waitForAsync async fn -> FAIL
With waitForAsync await whenStabale fn -> FAIL
With fakeAsync tick -> FAIL
With fakeAsync flush -> FAIL
With fakeAsync flushMicrotasks -> FAIL
With fakeAsync whenStable -> FAIL
Native async with sleep -> PASS

I'm missing something or doing something wrong?