How to test PrimeNG components?

[JHarrisGTI]

Hello! When I upgrade to PrimeNG 19, a number of my unit tests stopped working. While attempting to fix them, I'm having a lot of trouble querying for PrimeNG components and getting them to do stuff.

I made a small example showing the sort of thing I'm having trouble with: https://stackblitz.com/~/github.com/JHarrisGTI/multiselect-testing?initialPath=/?id=63276061 It has a jest branch and a karma branch. In both cases, you'll see 1 test failure because I can't query for the multiselect I've added to the page.

It would be great if we could get some documentation about how to unit test PrimeNG components.

[JHarrisGTI]

I wonder if this is related to this patch note regarding upgrading to Angular 19:

Update tests that relied on the Promise timing of effects to use await whenStable() or call .detectChanges() to trigger effects. For effects triggered during change detection, ensure they don't depend on the application being fully rendered or consider using afterRenderEffect(). Tests using faked clocks may need to fast-forward/flush the clock.