Mark font-stretch as deprecated

[ddbeck]

Summary

The spec calls this a "legacy" alias, so I took this to mean it's now deprecated.

Test results and supporting details

https://drafts.csswg.org/css-fonts-4/#font-stretch-prop

It feels a little weird to mark this up, given the strong support for the old name. But given our guidelines, that's how this ought to be.

I didn't make the change for the SVG attribute or css.properties.font.font_stretch_support, since I was less clear on how to handle those based on the spec. Guidance or suggestions welcome.

Related issues

See the corresponding change in web-features: web-platform-dx/web-features#2707.

[Elchi3]

Given the renaming throughout, I would expect the deprecation status for all of the relevant keys here:

• css.at-rules.font-face.font-stretch (done)
• css.properties.font-stretch (done)
• css.properties.font-stretch.percentage (done)
• css.properties.font.font_stretch_support (missing)
• svg.global_attributes.font-stretch (missing)

[Elchi3]

I didn't make the change for the SVG attribute or css.properties.font.font_stretch_support, since I was less clear on how to handle those based on the spec. Guidance or suggestions welcome.

Ah I should have read your PR description. For css.properties.font.font_stretch_support I think it is clear that the spec now changed to font-width, and so the place for font-stretch has now become font-width. For SVG, I would file an issue against the spec probably.

[caugner]

Instead of marking this as deprecated, shouldn't we merge this as an alternate_name into css.properties.font-width?

[ddbeck]

@Elchi3

For SVG, I would file an issue against the spec probably.

I started down this path, but found that the SVG spec doesn't really define these either—it just links out to other specs. It also says that, "In the future, any new properties that apply to SVG content will not gain presentation attributes." This suggests to me that we can just go ahead and apply to deprecation to svg.global_attributes.font-stretch. Done in cebd0ea.

For css.properties.font.font_stretch_support, since its representing support for font-stretch values I think maybe the correct thing is to rename it. I've done that in 82a1eb9.

@caugner

Instead of marking this as deprecated, shouldn't we merge this as an alternate_name into css.properties.font-width?

There are no guidelines for when to use a separate key versus an alternative_name or prefix. That said, my preference would be for alternative_name and prefix to be used only for non-standard prefixes and aliases (that otherwise have no differences with respect to the standard name, or else have partial_implementation).

This makes it much easier for web-features to consume the data, where we have to represent the relationship between the two features. If it were an alternative name, I'd have to manually set support data for the font-stretch feature.

[Elchi3]

I started down this path, but found that the SVG spec doesn't really define these either—it just links out to other specs. It also says that, "In the future, any new properties that apply to SVG content will not gain presentation attributes." This suggests to me that we can just go ahead and apply to deprecation to svg.global_attributes.font-stretch. Done in cebd0ea.

I checked in Safari 18.4 (https://jsfiddle.net/wjv73nb2/) and font-width as an SVG attribute works. See also WebKit/WebKit#31897 where the attribute was added to Source/WebCore/svg/svgattrs.in. So either this was against the spec or the spec is not clear enough about this.

So, I think I'm +1 on deprecating svg.global_attributes.font-stretch and I think I would like to see svg.global_attributes.font-width in #26069 (possibly marked non-standard and/or with an issue filed against SVG asking for clarification)

[Elchi3]

For css.properties.font.font_stretch_support, since its representing support for font-stretch values I think maybe the correct thing is to rename it. I've done that in 82a1eb9.

This works for me! 👍