fix(css): skip useGenericFontNames rule in @supports feature declarations

[kaigritun]

Summary

When a font property is used inside an @supports condition (e.g., @supports (font: -apple-system-body) {}), it's testing for browser support rather than actually setting a font. This should not trigger the 'Generic font family missing' error.

Before

@supports (font: -apple-system-body) {
  /* ... */
}

Would trigger: lint/a11y/useGenericFontNames: Generic font family missing.

After

No longer triggers the error for properties inside @supports feature declarations.

Changes

• Added is_in_supports_feature_declaration() helper function to check if a property is inside an @supports condition
• Updated rule to skip validation when inside CSS_SUPPORTS_FEATURE_DECLARATION nodes
• Added test cases for @supports with font and font-family properties
• Updated documentation to mention this exception

Test Plan

• Added test cases to valid.css:
  • @supports (font: -apple-system-body) { }
  • @supports (font-family: -apple-system) { }
• All existing tests pass

Closes #8845

[changeset-bot]

🦋 Changeset detected

Latest commit: 511a53c

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 13 packages

Name	Type
@biomejs/biome	Patch
@biomejs/cli-win32-x64	Patch
@biomejs/cli-win32-arm64	Patch
@biomejs/cli-darwin-x64	Patch
@biomejs/cli-darwin-arm64	Patch
@biomejs/cli-linux-x64	Patch
@biomejs/cli-linux-arm64	Patch
@biomejs/cli-linux-x64-musl	Patch
@biomejs/cli-linux-arm64-musl	Patch
@biomejs/wasm-web	Patch
@biomejs/wasm-bundler	Patch
@biomejs/wasm-nodejs	Patch
@biomejs/backend-jsonrpc	Patch

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[coderabbitai]

Walkthrough

This change extends the useGenericFontNames CSS lint rule to skip analysis of declarations inside @supports feature blocks. It adds a helper is_in_supports_feature_declaration to detect when a CssGenericProperty has a CSS_SUPPORTS_FEATURE_DECLARATION ancestor, and returns early for those cases. The rule documentation and tests were updated (including fixing a selector typo) to reflect the new behaviour.

Possibly related PRs

• fix(linter): false positive for noDuplicateFontNames #7156: Modifies the same use_generic_font_names lint and adjusts handling of font-family properties.
• fix(useGenericFontNames): handle CSS variable as last font-family value #8443: Adds an early-skip in the same lint rule for cases involving trailing CSS variables in font-family declarations.

Suggested reviewers

• siketyan
• ematipico

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and concisely describes the main change: skipping the useGenericFontNames rule within @supports feature declarations.
Description check	✅ Passed	The description is well-related to the changeset, explaining the rationale, implementation details, and test plan for skipping the rule in @supports declarations.
Linked Issues check	✅ Passed	The PR successfully addresses #8845 by implementing the core requirement: skipping the useGenericFontNames rule when properties appear inside @supports feature declarations.
Out of Scope Changes check	✅ Passed	All changes are directly scoped to the issue: rule implementation, helper function, test cases, and documentation updates for @supports handling.

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[kaigritun]

Added changeset as requested.

[ematipico]

Fixed by #8848