Bug 231609 – [ iOS15 iPad Debug ] imported/w3c/web-platform-tests/webmessaging/MessagePort_onmessage_start.any.worker.html is a flaky failure (reached unreachable code)

• Component: New Bugs
• Status: RESOLVED FIXED

[Eric Hutchison]

imported/w3c/web-platform-tests/webmessaging/MessagePort_onmessage_start.any.worker.html 

is a flaky failure on iOS15 Debug on iPad

History: https://results.webkit.org/?suite=layout-tests&test=imported%2Fw3c%2Fweb-platform-tests%2Fwebmessaging%2FMessagePort_onmessage_start.any.worker.html

Build: https://build.webkit.org/#/builders/265/builds/63

Results: https://build.webkit.org/results/Apple-iPadOS-15-Simulator-Debug-WK2-Tests/r283979%20(63)/results.html

Diff:
--- /Volumes/Data/worker/ipados-simulator-15-debug-tests-wk2/build/layout-test-results/imported/w3c/web-platform-tests/webmessaging/MessagePort_onmessage_start.any.worker-expected.txt
+++ /Volumes/Data/worker/ipados-simulator-15-debug-tests-wk2/build/layout-test-results/imported/w3c/web-platform-tests/webmessaging/MessagePort_onmessage_start.any.worker-actual.txt
@@ -1,3 +1,3 @@
 
-PASS MessageChannel: port.onmessage enables message queue
+FAIL MessageChannel: port.onmessage enables message queue assert_unreached: Reached unreachable code

[Radar WebKit Bug Importer]

<rdar://problem/84164701>

[Eric Hutchison]

Updated test expectations at https://trac.webkit.org/changeset/284020/webkit

[Chris Dumez]

The test has:
setTimeout(t.unreached_func(), 100);

So I think this means that it took more than 100ms for the message event to get dispatched. This is not too surprising that this test would be flaky, especially on slower configuration. The WPT test needs fixing here I believe.

[Chris Dumez]

Upstream pull request: https://github.com/web-platform-tests/wpt/pull/31317

[Chris Dumez]

Created attachment 442021 [details]
Patch

[EWS Watchlist]

This patch modifies the imported WPT tests. Please ensure that any changes on the tests (not coming from a WPT import) are exported to WPT. Please see https://trac.webkit.org/wiki/WPTExportProcess

[Chris Dumez]

ping review?

[EWS]

Committed r284686 (243406@main): <https://commits.webkit.org/243406@main>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 442021 [details].