Bug 256614

Summary:	REGRESSION(263724@main): [ Monterey+ ] TestWebKitAPI.ParserYieldTokenTests.AsyncScriptRunsWhenFetched frequently fails
Product:	WebKit	Reporter:	Robert Jenner <jenner>
Component:	Layout and Rendering	Assignee:	Ryosuke Niwa <rniwa>
Status:	RESOLVED FIXED
Severity:	Normal	CC:	bfulgham, rniwa, simon.fraser, webkit-bot-watchers-bugzilla, webkit-bug-importer, zalan
Priority:	P2	Keywords:	InRadar
Version:	WebKit Nightly Build
Hardware:	Unspecified
OS:	Unspecified
See Also:	https://bugs.webkit.org/show_bug.cgi?id=256353

Description Robert Jenner 2023-05-10 14:28:40 PDT

TestWebKitAPI.ParserYieldTokenTests.AsyncScriptRunsWhenFetched

is a fairly consistent failure on Monterey and up. It isn't a constant failure, but it fails more than it passes which is why I am calling it consistent. 


HISTORY:
https://results.webkit.org/?suite=api-tests&test=TestWebKitAPI.ParserYieldTokenTests.AsyncScriptRunsWhenFetched

FAILURE STDIO:
    TestWebKitAPI.ParserYieldTokenTests.AsyncScriptRunsWhenFetched
        
        /Volumes/Data/worker/Apple-Ventura-Release-Build/build/Tools/TestWebKitAPI/Tests/WebKitCocoa/ParserYieldTokenTests.mm:195
        Expected equality of these values:
          "Running async script."
          eventMessages[2]
            Which is: "Finished requesting async script."
        
        
        /Volumes/Data/worker/Apple-Ventura-Release-Build/build/Tools/TestWebKitAPI/Tests/WebKitCocoa/ParserYieldTokenTests.mm:196
        Expected equality of these values:
          "Finished requesting async script."
          eventMessages[3]
            Which is: "Running async script."

Comment 1 Radar WebKit Bug Importer 2023-05-10 14:54:52 PDT

<rdar://problem/109173614>

Comment 2 Robert Jenner 2023-05-10 15:17:21 PDT

I have reproduce the failure on Ventura Release ToT running as follows:


run-api-tests --no-build --release --verbose TestWebKitAPI.ParserYieldTokenTests.AsyncScriptRunsWhenFetched


I was also able to bisect to a specific regression point. This fails at 263724@main, but not at 263723@main. 

So it appears that https://commits.webkit.org/263724@main is the culprit here.

Comment 3 Ryosuke Niwa 2023-05-10 15:39:31 PDT

I don't know how this test was able to stay consistent until now. There is no basis that guarantees "Running async script" to happen before "Finished requesting async script".

Comment 4 Ryosuke Niwa 2023-05-10 20:43:07 PDT

Pull request: https://github.com/WebKit/WebKit/pull/13735

Comment 5 EWS 2023-05-10 22:34:42 PDT

Committed 263948@main (360db466f1b5): <https://commits.webkit.org/263948@main>

Reviewed commits have been landed. Closing PR #13735 and removing active labels.