[web-animations-1] Should ready / finished rejections be marked as handled?

[birtles]

In web-platform-tests/wpt#18932 there was some discussion about unhandled rejections for the .ready promise and I wasn't sure what the correct behavior should be.

This morning I discovered whatwg/streams#547 where for streams we decided to explicitly mark rejections for "state promises" like .ready as handled. I wonder if we should be doing the same for .ready and .finished for the Animation interface?

[flackr]

This sounds reasonable to me. I was honestly surprised that the ready promise rejected when we in fact "handled" the requested actions. I think it would make sense to do the same here.

[graouts]

Agreed.

[birtles]

I worked on an initial patch for this for Firefox which should include WPT for this spec change:

https://hg.mozilla.org/try/rev/54bc69142ded40d5a5e5b8fef909bfd3fe1dab3e#l6.2

[birtles]

WPT for this change: web-platform-tests/wpt#22314

[graouts]

For reference, this change's implementation is tracked as WebKit bug 209240.