Bug 188189 – Perform a microtask checkpoint before creating a custom element

• Status: RESOLVED
• Resolution: FIXED
• Component: DOM

[Frédéric Wang (:fredw)]

From https://html.spec.whatwg.org/multipage/parsing.html#create-an-element-for-the-token (step 6.2):

If will execute script is true, then: If the JavaScript execution context stack is empty, then perform a microtask checkpoint.

[Ryosuke Niwa]

Are there any WPT tests for this?

[Radar WebKit Bug Importer]

<rdar://problem/42843022>

[Frédéric Wang (:fredw)]

(In reply to Ryosuke Niwa from comment #1)
> Are there any WPT tests for this?

I think it is microtasks-and-constructors.html which we currently fails.

In addition to comment 0, the test and https://github.com/whatwg/html/issues/2381 also refer to microtask during element upgrade, but I can't find where it in the current version of the spec.

[Domenic Denicola]

The upgrade case is subtle.

https://html.spec.whatwg.org/multipage/custom-elements.html#concept-upgrade-an-element step 8.1 ->
https://heycam.github.io/webidl/#construct-a-callback-function ->
https://html.spec.whatwg.org/multipage/webappapis.html#clean-up-after-running-script ->
https://html.spec.whatwg.org/multipage/webappapis.html#perform-a-microtask-checkpoint (if the stack is empty at that time, i.e. if the UA is calling it)

[Ryosuke Niwa]

*** Bug 188284 has been marked as a duplicate of this bug. ***

[Ryosuke Niwa]

Created attachment 347118 [details]
Fixes the bug

[EWS Watchlist]

Comment on attachment 347118 [details]
Fixes the bug

Attachment 347118 [details] did not pass mac-ews (mac):
Output: https://webkit-queues.webkit.org/results/8860603

New failing tests:
fast/dom/MutationObserver/parser-mutations.html

[EWS Watchlist]

Created attachment 347127 [details]
Archive of layout-test-results from ews101 for mac-sierra

The attached test failures were seen while running run-webkit-tests on the mac-ews.
Bot: ews101  Port: mac-sierra  Platform: Mac OS X 10.12.6

[EWS Watchlist]

Comment on attachment 347118 [details]
Fixes the bug

Attachment 347118 [details] did not pass mac-wk2-ews (mac-wk2):
Output: https://webkit-queues.webkit.org/results/8860946

New failing tests:
fast/dom/MutationObserver/parser-mutations.html

[EWS Watchlist]

Created attachment 347133 [details]
Archive of layout-test-results from ews104 for mac-sierra-wk2

The attached test failures were seen while running run-webkit-tests on the mac-wk2-ews.
Bot: ews104  Port: mac-sierra-wk2  Platform: Mac OS X 10.12.6

[EWS Watchlist]

Comment on attachment 347118 [details]
Fixes the bug

Attachment 347118 [details] did not pass ios-sim-ews (ios-simulator-wk2):
Output: https://webkit-queues.webkit.org/results/8860804

New failing tests:
fast/dom/MutationObserver/parser-mutations.html

[EWS Watchlist]

Created attachment 347135 [details]
Archive of layout-test-results from ews123 for ios-simulator-wk2

The attached test failures were seen while running run-webkit-tests on the ios-sim-ews.
Bot: ews123  Port: ios-simulator-wk2  Platform: Mac OS X 10.13.4

[EWS Watchlist]

Comment on attachment 347118 [details]
Fixes the bug

Attachment 347118 [details] did not pass mac-debug-ews (mac):
Output: https://webkit-queues.webkit.org/results/8861012

New failing tests:
fast/dom/MutationObserver/parser-mutations.html

[EWS Watchlist]

Created attachment 347138 [details]
Archive of layout-test-results from ews115 for mac-sierra

The attached test failures were seen while running run-webkit-tests on the mac-debug-ews.
Bot: ews115  Port: mac-sierra  Platform: Mac OS X 10.12.6

[Ryosuke Niwa]

Created attachment 347143 [details]
Fixed the test

[Geoffrey Garen]

Comment on attachment 347143 [details]
Fixed the test

r=me

[Ryosuke Niwa]

Comment on attachment 347143 [details]
Fixed the test

Thanks!

[WebKit Commit Bot]

Comment on attachment 347143 [details]
Fixed the test

Clearing flags on attachment: 347143

Committed r234944: <https://trac.webkit.org/changeset/234944>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.

[Frédéric Wang (:fredw)]

Comment on attachment 347143 [details]
Fixed the test

View in context: https://bugs.webkit.org/attachment.cgi?id=347143&action=review

> Source/WebCore/dom/Document.cpp:5430
> +    // FIXME: Schdule a task to fire DOMContentLoaded event instead. See webkit.org/b/82931

nit: Schedule

> LayoutTests/ChangeLog:13
> +        * fast/custom-elements/perform-microtask-checkpoint-before-construction.html: Added.

Does it make sense to export this to the upstream WPT repo?

[Ryosuke Niwa]

Comment on attachment 347143 [details]
Fixed the test

View in context: https://bugs.webkit.org/attachment.cgi?id=347143&action=review

>> LayoutTests/ChangeLog:13
>> +        * fast/custom-elements/perform-microtask-checkpoint-before-construction.html: Added.
> 
> Does it make sense to export this to the upstream WPT repo?

Yes.

[darshan]

Created pull request https://github.com/web-platform-tests/wpt/pull/14221,

Second test is failing as of now.

[Ryosuke Niwa]

(In reply to darshan from comment #22)
> Created pull request https://github.com/web-platform-tests/wpt/pull/14221,
> 
> Second test is failing as of now.

Against which STP or trunk revision did you test this?

[darshan]

(In reply to Ryosuke Niwa from comment #23)
> (In reply to darshan from comment #22)
> > Created pull request https://github.com/web-platform-tests/wpt/pull/14221,
> > 
> > Second test is failing as of now.
> 
> Against which STP or trunk revision did you test this?
I did ./wpt serve in repo and open the test in chromium, I am using Chromium 70.0.3538.77

[Ryosuke Niwa]

(In reply to darshan from comment #24)
> (In reply to Ryosuke Niwa from comment #23)
> > (In reply to darshan from comment #22)
> > > Created pull request https://github.com/web-platform-tests/wpt/pull/14221,
> > > 
> > > Second test is failing as of now.
> > 
> > Against which STP or trunk revision did you test this?
> I did ./wpt serve in repo and open the test in chromium, I am using Chromium
> 70.0.3538.77

Okay, that's not too surprising because you're testing against Blink. Note that Chromium no longer uses WebKit. It uses an alternative engine called Blink, which was forked in 2013.

[darshan]

(In reply to Ryosuke Niwa from comment #25)
> (In reply to darshan from comment #24)
> > (In reply to Ryosuke Niwa from comment #23)
> > > (In reply to darshan from comment #22)
> > > > Created pull request https://github.com/web-platform-tests/wpt/pull/14221,
> > > > 
> > > > Second test is failing as of now.
> > > 
> > > Against which STP or trunk revision did you test this?
> > I did ./wpt serve in repo and open the test in chromium, I am using Chromium
> > 70.0.3538.77
> 
> Okay, that's not too surprising because you're testing against Blink. Note
> that Chromium no longer uses WebKit. It uses an alternative engine called
> Blink, which was forked in 2013.

Okay, so it means we can merge this PR in master?

[Frédéric Wang (:fredw)]

(In reply to darshan from comment #26)
> (In reply to Ryosuke Niwa from comment #25)
> > (In reply to darshan from comment #24)
> > > (In reply to Ryosuke Niwa from comment #23)
> > > > (In reply to darshan from comment #22)
> > > > > Created pull request https://github.com/web-platform-tests/wpt/pull/14221,
> > > > > 
> > > > > Second test is failing as of now.
> > > > 
> > > > Against which STP or trunk revision did you test this?
> > > I did ./wpt serve in repo and open the test in chromium, I am using Chromium
> > > 70.0.3538.77
> > 
> > Okay, that's not too surprising because you're testing against Blink. Note
> > that Chromium no longer uses WebKit. It uses an alternative engine called
> > Blink, which was forked in 2013.
> 
> Okay, so it means we can merge this PR in master?

@Darshan: Thanks for the PR. This bug is fixed in WebKit. If you are using a trunk build of WebKit then all the tests should pass. As Ryosuke said, Chromium does not use WebKit anymore so behavior might be different. Let's continue the discussion on github WPT.

[darshan]

Created new PR https://github.com/web-platform-tests/wpt/pull/14314,
Closed old PR(https://github.com/web-platform-tests/wpt/pull/14221), as I messed git history