css.properties.position-area / css.types.anchor() - animating not supported in Firefox

[jakearchibald]

What type of issue is this?

Incorrect support data (example: BrowserX says "86" but support was added in "40")

What information was incorrect, unhelpful, or incomplete?

https://codepen.io/jaffathecake/pen/PwzGrzw?editors=1100 - in Chrome & Safari, when you hover over items here, the 'highlight' animates into place. In Firefox, it doesn't animate.

https://bugzilla.mozilla.org/show_bug.cgi?id=1924226 - here's the bug.

This is a common 'trick' with anchor positioning. Developers will try to do this, and they'll be surprised when it doesn't work. It'd be nice if BCD captures this gap.

What browsers does this problem apply to, if applicable?

Firefox

What did you expect to see?

Something that clarifies that Firefox does not support this.

However, I couldn't figure out how to express/de-dupe this data. It feels like it needs to be captured on position-area/top/left/right/bottom/inset/width/height.

Did you test this? If so, how?

See above.

Can you link to any release notes, bugs, pull requests, or MDN pages related to this?

See above.

Do you have anything more you want to share?

No response

MDN URL

No response

MDN metadata

No response

[caugner]

Maybe we could document this in the support data for transition property, or add is_animatable//is_transitionable subfeatures on the properties. 🤔

PS: It would be nice if we could capture bugs/limitations in a central place, referencing the affected features, and "copying" the notes into the features at BCD build time.