fix(css_analyze): ignore at-rules supporting descriptors by Netail · Pull Request #8819 · biomejs/biome

Netail · 2026-01-20T18:03:20Z

Summary

Closes #6567, ignore unknown properties if located in at-rules supporting descriptors

Test Plan

Unit test

Docs

changeset-bot · 2026-01-20T18:03:24Z

🦋 Changeset detected

Latest commit: 7dfd40f

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

This PR includes changesets to release 14 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
@biomejs/prettier-compare	Patch

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codspeed-hq · 2026-01-20T18:12:47Z

Merging this PR will degrade performance by 15.64%

❌ 5 regressed benchmarks
✅ 24 untouched benchmarks
⏩ 126 skipped benchmarks¹

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Benchmark	`BASE`	`HEAD`	Efficiency
❌	`css_analyzer[bootstrap_18416142857265205439.css]`	478.9 ms	515.6 ms	-7.11%
❌	`css_analyzer[bulma_5641719244145477318.css]`	1.1 s	1.2 s	-8.92%
❌	`css_analyzer[foundation_11602414662825430680.css]`	165.4 ms	191.3 ms	-13.54%
❌	`css_analyzer[tachyons_11778168428173736564.css]`	123.4 ms	140.9 ms	-12.41%
❌	`css_analyzer[pure_9395922602181450299.css]`	17.1 ms	20.3 ms	-15.64%

_{Comparing Netail:fix/ignore-at-rules-supporting-discriptors (7dfd40f) with main (b08270b)²}

126 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩
No successful run was found on main (ad283bb) during the generation of this report, so b08270b was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

coderabbitai · 2026-01-20T18:14:07Z

Walkthrough

Broads the noUnknownProperty lint to detect any AnyCssAtRule ancestor and, unless that ancestor is one of the explicitly enumerated descriptor-supporting at-rules, treat the context as supporting descriptors and skip reporting unknown properties. Adds a new public node union AnyDescriptorSupportingAtRules (union of TwApplyAtRule, CssContainerAtRule, CssLayerAtRule, CssMediaAtRule, CssScopeAtRule, CssStartingStyleAtRule, CssSupportsAtRule), updates imports, and adds tests (valid/invalid at-rule cases) plus a changeset entry. No other public APIs changed.

Possibly related PRs

fix(noUnknownProperty): don't flag anything in @plugin #8403 — Adjusts the same no_unknown_property lint to skip diagnostics inside plugin-like at-rules using ancestor-based detection.

Suggested reviewers

ematipico
dyc3

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and concisely summarizes the main change: modifying CSS analysis to ignore at-rules supporting descriptors in the noUnknownProperty rule.
Description check	✅ Passed	The description accurately relates to the changeset, referencing issue `#6567` and explaining the intent to ignore unknown properties in descriptor-supporting at-rules with a test plan.
Linked Issues check	✅ Passed	The code changes directly address issue `#6567` by modifying noUnknownProperty to ignore declarations within at-rules supporting descriptors, with new test cases validating the behaviour.
Out of Scope Changes check	✅ Passed	All changes are focused on the noUnknownProperty rule and related tests; formatting updates in valid.css and test configuration files are incidental and appropriately scoped.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing touches

📝 Generate docstrings

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coderabbitai

Actionable comments posted: 1

🤖 Fix all issues with AI agents

In `@crates/biome_css_analyze/src/lint/correctness/no_unknown_property.rs`:
- Around line 82-101: The current ancestor check for
is_at_rule_supporting_descriptors uses an exclusion-style test (AnyCssAtRule
with a list of denied kinds) and thus incorrectly treats most at-rules as
descriptor-supporting; change it to an inclusive allow-list that returns true
only when an ancestor.kind() is one of the known descriptor-supporting at-rules
(e.g. match AnyCssAtRule::can_cast(ancestor.kind()) and then explicitly check
for the allowed kinds such as the enum variants representing `@font-face`,
`@font-feature-values`, `@property`, `@counter-style`, and `@viewport`), otherwise
return false; update the is_at_rule_supporting_descriptors computation (and any
references to it) so validation is skipped only for those allowed at-rules.

crates/biome_css_analyze/src/lint/correctness/no_unknown_property.rs

ematipico

Should address the parsing diagnostics

ematipico · 2026-01-21T07:46:33Z

crates/biome_css_analyze/src/lint/correctness/no_unknown_property.rs

+        let is_at_rule_supporting_descriptors = node.syntax().ancestors().any(|ancestor| {
+            if AnyCssAtRule::can_cast(ancestor.kind())
+                && !(TwApplyAtRule::can_cast(ancestor.kind())
+                    || CssContainerAtRule::can_cast(ancestor.kind())
+                    || CssLayerAtRule::can_cast(ancestor.kind())
+                    || CssMediaAtRule::can_cast(ancestor.kind())
+                    || CssScopeAtRule::can_cast(ancestor.kind())
+                    || CssStartingStyleAtRule::can_cast(ancestor.kind())
+                    || CssSupportsAtRule::can_cast(ancestor.kind()))
+            {
+                return true;
+            }
+
+            false


Two things:

why did we remove skip()?

in these cases, it's best to create a new node via declare_node_union. The code becomes more readable

ematipico · 2026-01-21T07:47:30Z

crates/biome_css_analyze/tests/specs/correctness/noUnknownProperty/valid.at-rules.css.snap

+
+```
+
+_Note: The parser emitted 2 diagnostics which are not shown here._


This seems important. There are parsing errors, and I believe you don't want to test broken syntax

Oops, didn't notice. Some syntax that would be valid with scss 😅

ematipico

Looks good. A couple of things to address

ematipico · 2026-01-21T16:00:12Z

crates/biome_css_analyze/src/lint/correctness/no_unknown_property.rs

 }
+
+declare_node_union! {
+    pub DescriptorSupportingAtRules = TwApplyAtRule | CssContainerAtRule


Suggested change

pub DescriptorSupportingAtRules = TwApplyAtRule | CssContainerAtRule

pub AnyDescriptorSupportingAtRules = TwApplyAtRule | CssContainerAtRule

As per internal coding guidelines, all unions must start with Any*

ematipico · 2026-01-21T16:01:07Z

.changeset/tough-pans-greet.md

+"@biomejs/biome": patch
+---
+
+Fixed [#6567](https://github.com/biomejs/biome/issues/6567). Ignore unknown properties in at-rules which support descriptors.


You might want to mention the rule. Without clicking the issue, there's little context, and it gets difficult to understand what's been fixed and where

github-actions bot added A-Linter Area: linter L-CSS Language: CSS labels Jan 20, 2026

coderabbitai bot reviewed Jan 20, 2026

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crates/biome_css_analyze/src/lint/correctness/no_unknown_property.rs Outdated Show resolved Hide resolved

fix(css_analyze): ignore at-rules supporting descriptors

6a8ba12

Netail force-pushed the fix/ignore-at-rules-supporting-discriptors branch from d7fe7c9 to 6a8ba12 Compare January 20, 2026 18:52

ematipico requested changes Jan 21, 2026

View reviewed changes

fix: feedback

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Netail requested a review from ematipico January 21, 2026 09:59

ematipico approved these changes Jan 21, 2026

View reviewed changes

fix: feedback

7dfd40f

Netail merged commit bc191ff into biomejs:main Jan 23, 2026
17 of 18 checks passed

Netail deleted the fix/ignore-at-rules-supporting-discriptors branch January 23, 2026 10:46

github-actions bot mentioned this pull request Jan 23, 2026

ci: release #8671

Merged

This was referenced Jan 23, 2026

fix(css): ignore @supports queries in useGenericFontNames rule #8848

Merged

feat(css): add support for the @function CSS at rule #8839

Merged

coderabbitai bot mentioned this pull request Feb 21, 2026

fix(css): skip useGenericFontNames rule inside @supports at-rules #8946

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fix(css_analyze): ignore at-rules supporting descriptors#8819

fix(css_analyze): ignore at-rules supporting descriptors#8819
Netail merged 3 commits intobiomejs:mainfrom
Netail:fix/ignore-at-rules-supporting-discriptors

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		```

		_Note: The parser emitted 2 diagnostics which are not shown here._

	pub DescriptorSupportingAtRules = TwApplyAtRule \| CssContainerAtRule
	pub AnyDescriptorSupportingAtRules = TwApplyAtRule \| CssContainerAtRule

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Netail commented Jan 20, 2026

Summary

Test Plan

Docs

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Merging this PR will degrade performance by 15.64%

Performance Changes

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