Bug 250438

Summary: tiled-drawing/scrolling/scroll-snap tests fail with UI-side compositing
Product: WebKit Reporter: Simon Fraser (smfr) <simon.fraser>
Component: Tools / TestsAssignee: Simon Fraser (smfr) <simon.fraser>
Status: RESOLVED FIXED    
Severity: Normal CC: webkit-bug-importer
Priority: P2 Keywords: InRadar
Version: WebKit Local Build   
Hardware: Unspecified   
OS: Unspecified   

Description Simon Fraser (smfr) 2023-01-10 21:55:07 PST
These tests do things like:

    eventSender.keyDown("rightArrow");
    expectTrue(document.scrollingElement.scrollLeft == (window.innerWidth * scale), "arrow key div scrolled to second div.");

With UI-side compositing, arrow handling hits AsyncScrollingCoordinator::requestScrollPositionUpdate(), which bounces to the UI process, and then IPCs back to the web process via AsyncScrollingCoordinator::reconcileScrollingState() which updates the ScrollableArea's scroll position, which is then read by `scrollLeft`.

So the tests need to wait for a presentation update after dispatching the key.
Comment 1 Radar WebKit Bug Importer 2023-01-10 21:55:43 PST
<rdar://problem/104108634>
Comment 2 Simon Fraser (smfr) 2023-01-10 21:56:52 PST
Pull request: https://github.com/WebKit/WebKit/pull/8510
Comment 3 EWS 2023-01-11 09:53:27 PST
Committed 258790@main (0a58ac14fcc1): <https://commits.webkit.org/258790@main>

Reviewed commits have been landed. Closing PR #8510 and removing active labels.