[ macOS wk1 ] editing/execCommand/insert-nested-lists.html is flaky failing

[Jacob Uphoff]

editing/execCommand/insert-nested-lists.html

This flaky failure has been happening for all visible history on Catalina and Mojave

I was able to reproduce by running the test in iterations

History:

https://results.webkit.org/?suite=layout-tests&test=editing%2FexecCommand%2Finsert-nested-lists.html

Diff:

https://build.webkit.org/results/Apple-Catalina-Debug-WK1-Tests/r255510%20(2186)/editing/execCommand/insert-nested-lists-diff.txt

[Jacob Uphoff]

Created attachment 389398 [details]
Update Test Expectations

[Radar WebKit Bug Importer]

<rdar://problem/59072372>

[Truitt Savell]

Comment on attachment 389398 [details]
Update Test Expectations

Clearing flags on attachment: 389398

Committed r255520: <https://trac.webkit.org/changeset/255520>

[Alexey Proskuryakov]

Presumably this part is insufficient to deflake it?

    // By default, AppKit on macOS coalesces undo operations that occur within the same runloop. Wait until the next
    // runloop before inserting another unordered list to ensure that it gets its own entry in the undo stack.
    await new Promise((resolve) => {
        if (window.testRunner)
            testRunner.runUIScript(`(function() { uiController.uiScriptComplete(); })()`, resolve);
        else
            setTimeout(resolve, 500);
    });

[Ryosuke Niwa]

(In reply to Alexey Proskuryakov from comment #4)
> Presumably this part is insufficient to deflake it?
> 
>     // By default, AppKit on macOS coalesces undo operations that occur
> within the same runloop. Wait until the next
>     // runloop before inserting another unordered list to ensure that it
> gets its own entry in the undo stack.
>     await new Promise((resolve) => {
>         if (window.testRunner)
>             testRunner.runUIScript(`(function() {
> uiController.uiScriptComplete(); })()`, resolve);
>         else
>             setTimeout(resolve, 500);
>     });

Hm... going to the UI script in theory should be sufficient but I guess not.

[Wenson Hsieh]

(In reply to Ryosuke Niwa from comment #5)
> (In reply to Alexey Proskuryakov from comment #4)
> > Presumably this part is insufficient to deflake it?
> > 
> >     // By default, AppKit on macOS coalesces undo operations that occur
> > within the same runloop. Wait until the next
> >     // runloop before inserting another unordered list to ensure that it
> > gets its own entry in the undo stack.
> >     await new Promise((resolve) => {
> >         if (window.testRunner)
> >             testRunner.runUIScript(`(function() {
> > uiController.uiScriptComplete(); })()`, resolve);
> >         else
> >             setTimeout(resolve, 500);
> >     });
> 
> Hm... going to the UI script in theory should be sufficient but I guess not.

I’m not sure if runUIScript is sufficient to ensure that the we proceed after the next runloop in WebKit1. Maybe we need to call uiController.doAsyncTask() instead?