207847 2020-02-17 10:29:07 -0800 REGRESSION: (r256232) [ Mac wk1 Release ] resize-observer/delete-observers-in-callbacks.html is flaky failing. 2020-03-13 15:35:15 -0700 1 1 1 Unclassified WebKit New Bugs WebKit Nightly Build Mac macOS 10.14 RESOLVED FIXED InRadar P2 Normal --- 1 Lawrence.j cdumez cdumez jacob_uphoff simon.fraser webkit-bot-watchers-bugzilla webkit-bug-importer oldest_to_newest 1619714 0 Lawrence.j 2020-02-17 10:29:07 -0800 resize-observer/delete-observers-in-callbacks.html Description: This test is flaky failing on Mac wk1 Release. The first recorded failure appears to be at r256232. History: https://results.webkit.org/?limit=50000&suite=layout-tests&test=resize-observer%2Fdelete-observers-in-callbacks.html&platform=mac Diff: --- /Volumes/Data/slave/catalina-release-tests-wk1/build/layout-test-results/resize-observer/delete-observers-in-callbacks-expected.txt +++ /Volumes/Data/slave/catalina-release-tests-wk1/build/layout-test-results/resize-observer/delete-observers-in-callbacks-actual.txt @@ -1,5 +1,5 @@ t1 -PASS ResizeObserver implemented -PASS Test deleting observer in callbacks +FAIL ResizeObserver implemented assert_own_property: expected property "ResizeObserver" missing +FAIL Test deleting observer in callbacks promise_test: Unhandled rejection with value: object "ReferenceError: Can't find variable: ResizeObserver" 1619716 1 webkit-bug-importer 2020-02-17 10:29:29 -0800 <rdar://problem/59516099> 1619719 2 Lawrence.j 2020-02-17 10:34:07 -0800 I have marked this test as failing while this issue is investigated. https://trac.webkit.org/changeset/256744/webkit 1619957 3 jacob_uphoff 2020-02-17 15:52:05 -0800 Reproducible by running the test in iterations. Ran this command: 'run-webkit-tests --root release-256766 resize-observer/delete-observers-in-callbacks.html -1 -f --iterations 5000' and failed 8 times. 1619958 4 jacob_uphoff 2020-02-17 16:03:51 -0800 Looks like it might not be a recent regression, I have run the test back to commit 256422 and am seeing the failure there. It is curious because the failures will happen pretty early on in the iteration runs then pass for the rest of them. Results: [8/5002] resize-observer/delete-observers-in-callbacks.html failed unexpectedly (text diff) [8/5002] resize-observer/delete-observers-in-callbacks.html failed unexpectedly (text diff) [10/5002] resize-observer/delete-observers-in-callbacks.html failed unexpectedly (text diff) [11/5002] resize-observer/delete-observers-in-callbacks.html failed unexpectedly (text diff) [12/5002] resize-observer/delete-observers-in-callbacks.html failed unexpectedly (text diff) [18/5002] resize-observer/delete-observers-in-callbacks.html failed unexpectedly (text diff) [22/5002] resize-observer/delete-observers-in-callbacks.html failed unexpectedly (text diff) [24/5002] resize-observer/delete-observers-in-callbacks.html failed unexpectedly (text diff) No handlers could be found for logger "webkitpy.common.interrupt_debugging" Retrying 1 unexpected failure ... Running 1 DumpRenderTree. [1/1] resize-observer/delete-observers-in-callbacks.html failed unexpectedly (text diff) 4994 tests ran as expected, 8 didn't: 1619976 5 Lawrence.j 2020-02-17 16:46:59 -0800 I am able to reproduce this issue with r256232, but not with r256231 using this command: run-webkit-tests resize-observer/delete-observers-in-callbacks.html --force -f --iterations 5000 --exit-after-n-failures 5 -1 1629805 6 cdumez 2020-03-13 13:37:26 -0700 Looks like ResizeObserver is enabled by a setting: EnabledBySetting=ResizeObserver 1629807 7 cdumez 2020-03-13 13:40:18 -0700 The test also uses the following header: <!DOCTYPE html> 1629824 8 cdumez 2020-03-13 13:59:29 -0700 (In reply to Chris Dumez from comment #7) > The test also uses the following header: > <!DOCTYPE html> The issue is that some settings can be set either via internals JS API or via . Depending on which order you do these things, you'll end up with a different results. Also, to make things more complicated, once the window object has been created, changes to the ResizeObserverEnabled setting are no longer reflected on that Window object. It is important that ResizeObserverEnabled setting be enabled *before* we construct the window. 1629889 9 cdumez 2020-03-13 15:32:54 -0700 Reverted guilty patch in <https://trac.webkit.org/changeset/258438>. 1629890 10 cdumez 2020-03-13 15:35:15 -0700 Committed r258440: <https://trac.webkit.org/changeset/258440>