web-platform-tests / web-platform-tests/interop

CSS @function

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focus-area-proposal
Dominant language
JavaScript
Stars
524
Forks
35
Avg merge
1d 4h
Merged PRs (30d)
10

Description

Description

The @function CSS at-rule enables defining CSS custom functions. Once defined, a custom function can be called using the syntax (for example, --my-function(30px, 3)) within any property value.

This feature has shipped in Chrome 139, with Safari including it in Safari Tech Preview 249.

Specification

https://www.w3.org/TR/css-mixins-1/#function-rule

web-feature

https://web-platform-dx.github.io/web-features-explorer/features/function/

Test Links

https://wpt.fyi/results/css/css-mixins/functions?label=experimental&label=master&aligned

Additional Signals

Contributor guide

No contributing guide indexed for this repository

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

The issue names no repository file or concrete change. Start with the CSS Mixins Level 1 @function specification, then inspect the linked WPT results and the repository’s contribution guidance to identify the relevant coverage or configuration entry point. Done should be defined by the missing project change and corresponding test coverage, which the issue currently does not specify.

Written by the indexing model from the issue text.

Assessment

Tech stack
css
Domain
testing-qa, web-dev
Issue type
Feature
Difficulty
3/5
Estimated time
1-2 days
Activity status
Active
Clarity
Needs clarification
Newbie friendliness
48/100

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