Summary: LayoutTests/js/dom/Promise-static-all/race.html are flakey - Unhandled Promise Rejection messages The layout tests creates two rejected promises p7, and p8 but does nothing with them. They are legitimate unhandled promise rejections. These promises can get garbage collected during the test run. So the logs depend on whether or not they get GC'd before the RejectionTracker's task happens. I'm going to silence the unhandledrejection errors in these tests.
> These promises can get garbage collected during the test run. Hmm, actually I don't think thats true. They are in window.p7 and window.p8. Either way, I think disabling the messages is the right thing to do but I'll look into this a bit more.
Running the test in the browser I always see the unhandled rejection errors, which is the behavior I would expect. The messages are not important for this test so I'm going to silence them. There may be some subtle issue here regarding the order of operations between microtasks and tasks, but again not important for this test and not particularly important in general for these optional events.
Created attachment 308585 [details] [PATCH] Proposed Fix
For reference: https://build.webkit.org/results/Apple%20iOS%2010%20Simulator%20Release%20WK2%20(Tests)/r215929%20(1023)/results.html The diffs look like: --- /Volumes/Data/slave/ios-simulator-10-release-tests-wk2/build/layout-test-results/js/dom/Promise-static-all-expected.txt +++ /Volumes/Data/slave/ios-simulator-10-release-tests-wk2/build/layout-test-results/js/dom/Promise-static-all-actual.txt @@ -1,3 +1,5 @@ +CONSOLE MESSAGE: line 1: Unhandled Promise Rejection: p7 +CONSOLE MESSAGE: line 1: Unhandled Promise Rejection: p8 Test Promise.all On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
<https://trac.webkit.org/r215938>
I'm still seeing LayoutTest js/dom/Promise-static-all.html fail as of revision r215953 History: https://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=js%2Fdom%2FPromise-static-all.html Build Log https://build.webkit.org/results/Apple%20iOS%2010%20Simulator%20Release%20WK2%20(Tests)/r215953%20(1036)/results.html
Reopening this per Matt's comment.
Comment on attachment 308585 [details] [PATCH] Proposed Fix View in context: https://bugs.webkit.org/attachment.cgi?id=308585&action=review > LayoutTests/js/dom/Promise-static-all.html:13 > +// window.onunhandledrejection = () => false; Oops, this line was commented out by accident.
Fixed in: https://trac.webkit.org/r215966 Thanks for pointing it out!