1830512 - (@scope) Add support for @scope

Status: NEW

(Core :: CSS Parsing and Computation, enhancement)

Description

[Sebastian Zartner [:sebo]]

The CSS Cascading and Inheritance Module Level 6 introduces an @scope rule that restricts any rules inside it to a subtree or fragment of a document.

This bug is meant to track the implementation of this at-rule.

Sebastian

Comment 1

[Oliver Medhurst [:canadahonk]]

For context, Chrome is planning to ship this in M118 (~October) and it is soon to be enabled by default in Canary. Their intent to ship: https://groups.google.com/a/chromium.org/g/blink-dev/c/OEfGbd74QnQ/m/KaX-2hhRAAAJ

Comment 2

[keithjgrant]

Safari has also shipped this in the latest Tech Preview: https://developer.apple.com/documentation/safari-technology-preview-release-notes/stp-release-185

Comment 3

[Frank Griffith Jr]

In the radar for H1 2024 via https://mozilla-hub.atlassian.net/browse/FFXP-1523

Comment 4

[Daniel Holbert [:dholbert] (mostly-away until Aug 19)]

RE interop-2024-starting-style relationship: that's [at least] for this test, which uses @scope and is part of that interop-2024 focus area:
https://wpt.fyi/results/css/css-cascade/scope-starting-style.html
http://wpt.live/css/css-cascade/scope-starting-style.html

Comment 5

[Emilio Cobos Álvarez (:emilio)]

We should probably exclude those from interop then, fwiw.

Comment 6

[Daniel Holbert [:dholbert] (mostly-away until Aug 19)]

Makes sense. I filed https://github.com/web-platform-tests/interop/issues/641 to remove that test.

(I think it's just the one test that uses @scope.)

Comment 8

[Sebastian Zartner [:sebo]]

For reference, the intent to prototype @scope was posted at https://groups.google.com/a/mozilla.org/g/dev-platform/c/VokGNgqFqt0.

Sebastian