1937568 - Console warning when using h1 in article/aside/nav/section without author-defined font-size or block margins

Status: RESOLVED FIXED

(Core :: Layout, task)

Description

[Simon Pieters [:zcorpan]]

See https://github.com/whatwg/html/issues/7867#issuecomment-2541654834

I envisioned logging a message when h1 in a sectioning element is rendered but doesn't have author-defined font-size or block margins. When the change has shipped everywhere, there's no need for the warning anymore.

This would need to differentiate author-origin styles vs UA-origin styles.

Comment 1

[Simon Pieters [:zcorpan]]

From discussion with :emilio

We have ways to know whether a property is author-specified
But it'd be a bit expensive having to walk the ancestor chain unconditionally

Maybe we can have a UA-origin-only custom property added to the UA stylesheet

:is(section, aside, article, nav) h1 { -moz-has-sectioning-ancestor: 1 }

Then check the value of that somewhere?

Well sure, that'd at least use the bloom filter I think
Still probably overkill

Comment 2

[Simon Pieters [:zcorpan]]

A use counter would be nice here also.

Comment 3

[Emilio Cobos Álvarez (:emilio)]

Attachment: Bug 1937568 - Use counter and warning for <h1> inside section/etc with no margin or font-size. r=zcorpan

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/da66c6c0feb4
Use counter and warning for <h1> inside section/etc with no margin or font-size. r=zcorpan,flod

Comment 5

[amarc]

https://hg.mozilla.org/mozilla-central/rev/da66c6c0feb4

Comment 6

[Simon Pieters [:zcorpan]]

Attachment: Bug 1937568 - Fix MDN link in console warning for h1 font-size. r=emilio!

Comment 7

[BugBot [:suhaib / :marco/ :calixte]]

A patch has been attached on this bug, which was already closed. Filing a separate bug will ensure better tracking. If this was not by mistake and further action is needed, please alert the appropriate party. (Or: if the patch doesn't change behavior -- e.g. landing a test case, or fixing a typo -- then feel free to disregard this message)

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/73dd35269a01
Fix MDN link in console warning for h1 font-size. r=emilio

Comment 9

[Sandor Molnar[:smolnar]]

https://hg.mozilla.org/mozilla-central/rev/73dd35269a01