1299097 - @counter-style lacking minimum required descriptors should still show up in the OM

Status: NEW

(Core :: CSS Parsing and Computation, defect, P3)

Description

[Sebastian Zartner [:sebo]]

If you create a style sheet containing an empty @counter-style rule, it is not available through the CSSStyleSheet.cssRules property in opposite to other at-rules.

I realized this when trying to fix https://github.com/LeaVerou/css3test/issues/149.
See the attached URL for a test case, where the console output is expected to look like this:

CSSRuleList [ CSSKeyframesRule, CSSCounterStyleRule, CSSCounterStyleRule ]

but what you see is this:

CSSRuleList [ CSSKeyframesRule, CSSCounterStyleRule ]

Sebastian

Comment 1

[Andrew Overholt [:overholt]]

Cameron, this feels like it's in your wheelhouse.

Comment 2

[Xidorn Quan [:xidorn] UTC+10]

This was intentionally. The original CSS Counter Styles spec states that a @counter-style rule without "system" and some other descriptors is invalid, and thus should not be in the OM at all.

However, the CSSWG recently resolved in w3c/csswg-drafts#1133 to not ignore @font-face rule even when it lacks necessary descriptors, and thinks we should keep consistency on @counter-style rules as well, which means empty @counter-style rules should show up in the OM. It just shouldn't define a counter style.

Comment 3

[Cameron McCormack (:heycam)]

The CSSWG did end up resolving to keep empty @counter-style in the OM, per the paragraph just below https://drafts.csswg.org/css-counter-styles/#typedef-symbol.