Bug 284096 – REGRESSION (286687@main): [ iOS ] WPT test scroll-animations/css/scroll-timeline-responsiveness-from-endpoint.html is a failure.

• Status: NEW
• Component: Scrolling

[Ben Schwartz]

imported/w3c/web-platform-tests/scroll-animations/css/scroll-timeline-responsiveness-from-endpoint.html

This test is consistently failing on iOS 18.

HISTORY:

None, as we don't currently run automated iOS 18 correctness tests in CI.

TEXT DIFF:

-PASS Test that the scroll animation is still responsive after moving from 100%
+FAIL Test that the scroll animation is still responsive after moving from 100% assert_equals: Width after reset to scroll top expected "100px" but got "200px"

REGRESSION:

It appears this regressed with the changes at 286687@main.

[Radar WebKit Bug Importer]

<rdar://problem/140963948>

[EWS]

Test gardening commit 287387@main (9d6b134a5747): <https://commits.webkit.org/287387@main>

Reviewed commits have been landed. Closing PR #37484 and removing active labels.

[Ben Schwartz]

This test too: imported/w3c/web-platform-tests/scroll-animations/view-timelines/fieldset-source.html

[Ben Schwartz]

^ that test is constantly failing on iOS 17 and 18.

[EWS]

Test gardening commit 287434@main (52d16c972a16): <https://commits.webkit.org/287434@main>

Reviewed commits have been landed. Closing PR #37534 and removing active labels.

[Antoine Quint]

As it turns out scroll-animations/view-timelines/fieldset-source.html is simply completely broken. Fixing it will remove the iOS failures.

[Antoine Quint]

For `scroll-animations/css/scroll-timeline-responsiveness-from-endpoint.html`, the flaky assertion is the final assertion. Adding another call to `await waitForNextFrame()` prior to it makes the test run reliably.

[Antoine Quint]

Let's have this bug cover scroll-animations/css/scroll-timeline-responsiveness-from-endpoint.html only, as it was originally. I've filed bug 292191 for imported/w3c/web-platform-tests/scroll-animations/view-timelines/fieldset-source.html.

[Antoine Quint]

Having talked with Simon Fraser about this, this is expected with our current scrolling architecture. Moving this out to the Scrolling component then.