stylelint · romainmenke · Nov 27, 2025 · Nov 26, 2025 · Nov 26, 2025 · Nov 26, 2025
diff --git a/.changeset/eight-cars-switch.md b/.changeset/eight-cars-switch.md
@@ -0,0 +1,5 @@
+---
+"stylelint": patch
+---
+
+Fixed: `*-no-unknown` false positives for latest specs by integrating `@csstools/css-syntax-patches-for-csstree`
diff --git a/lib/lintPostcssResult.cjs b/lib/lintPostcssResult.cjs
diff --git a/lib/lintPostcssResult.mjs b/lib/lintPostcssResult.mjs
@@ -1,15 +1,21 @@
 import { EOL } from 'node:os';
+import { createRequire } from 'node:module';
 
 import { DEFAULT_SEVERITY, RULE_NAME_ALL } from './constants.mjs';
 import { DEFAULT_CONFIGURATION_COMMENT } from './utils/configurationComment.mjs';
 import assignDisabledRanges from './assignDisabledRanges.mjs';
 import { emitDeprecationWarning } from './utils/emitWarning.mjs';
 import { fork } from 'css-tree';
 import getStylelintRule from './utils/getStylelintRule.mjs';
+import mergeSyntaxDefinitions from './utils/mergeSyntaxDefinitions.mjs';
 import reportUnknownRuleNames from './reportUnknownRuleNames.mjs';
 import rules from './rules/index.mjs';
 import timing from './timing.mjs';
 
+/** @todo leverage import attributes once support for Node.js v18.19 is dropped */
+const require = createRequire(import.meta.url);
+const syntaxPatches = require('@csstools/css-syntax-patches-for-csstree/dist/index.json').next;
+
 /** @import {Config, LinterOptions, PostcssResult} from 'stylelint' */
 
 /**
@@ -171,12 +177,12 @@ function getCachedLexer(config) {
 		return lexerCache.get(cacheKey);
 	}
 
-	const newLexer = fork({
-		atrules: config.languageOptions?.syntax?.atRules || {},
-		properties: config.languageOptions?.syntax?.properties || {},
-		types: config.languageOptions?.syntax?.types || {},
-		cssWideKeywords: config.languageOptions?.syntax?.cssWideKeywords || [],
-	}).lexer;
+	const newLexer = fork(
+		mergeSyntaxDefinitions(syntaxPatches, {
+			...config.languageOptions?.syntax,
+			atrules: config.languageOptions?.syntax?.atRules,
+		}),
+	).lexer;
 
 	lexerCache.set(cacheKey, newLexer);
 

diff --git a/lib/rules/declaration-property-value-no-unknown/__tests__/index.mjs b/lib/rules/declaration-property-value-no-unknown/__tests__/index.mjs
@@ -41,6 +41,9 @@ testRule({
 		{
 			code: 'a { color: lightgray; }',
 		},
+		{
+			code: 'a { color: oklch(from red l c calc(h / 2) / alpha); }',
+		},
 		{
 			code: 'a { display: -moz-inline-stack; }',
 		},
@@ -186,6 +189,31 @@ testRule({
 					red;
 			}`,
 		},
+		{
+			code: 'a { height: calc-size(auto, size); }',
+		},
+		{
+			code: 'a { transition-timing-function: linear(0 0%, 0.999 44.8%, 0.866 58.4%, 0.998 77.2%, 1 100%) }',
+		},
+		{
+			code: 'a { container-type: scroll-state }',
+		},
+		{
+			code: 'a { inset: anchor(center) }',
+		},
+		{
+			code: stripIndent`a {
+				background: linear-gradient(in hsl longer hue, red, red);
+				background: radial-gradient(in hsl longer hue, red, red);
+				background: conic-gradient(in hsl longer hue, red, red);
+				background: repeating-linear-gradient(in hsl longer hue, red, red 50px);
+				background: repeating-radial-gradient(in hsl longer hue, red, red 50px);
+				background: repeating-conic-gradient(in hsl longer hue, red 0%, yellow 15%, red 33%);
+			}`,
+		},
+		{
+			code: 'a { appearance: base-select }',
+		},
 	],
 
 	reject: [
@@ -459,6 +487,24 @@ testRule({
 			endColumn: 31,
 			description: 'too few arguments in rgba()',
 		},
+		{
+			code: 'a { color: rgb(from red, r, g, b); }',
+			message: messages.rejected('color', 'rgb(from red, r, g, b)'),
+			line: 1,
+			column: 12,
+			endLine: 1,
+			endColumn: 34,
+			description: 'legacy syntax does not support relative colors',
+		},
+		{
+			code: 'a { color: rgb(from red l c h); }',
+			message: messages.rejected('color', 'rgb(from red l c h)'),
+			line: 1,
+			column: 12,
+			endLine: 1,
+			endColumn: 31,
+			description: 'component keywords are specific to each color function',
+		},
 	],
 });
 

diff --git a/lib/rules/declaration-property-value-no-unknown/index.cjs b/lib/rules/declaration-property-value-no-unknown/index.cjs
diff --git a/lib/rules/declaration-property-value-no-unknown/index.mjs b/lib/rules/declaration-property-value-no-unknown/index.mjs
@@ -1,4 +1,5 @@
 import { find, fork, parse, string } from 'css-tree';
+import { createRequire } from 'node:module';
 
 import { isRegExp, isString } from '../../utils/validateTypes.mjs';
 import { atRuleRegexes } from '../../utils/regexes.mjs';
@@ -12,12 +13,17 @@ import isStandardSyntaxDeclaration from '../../utils/isStandardSyntaxDeclaration
 import isStandardSyntaxProperty from '../../utils/isStandardSyntaxProperty.mjs';
 import isStandardSyntaxValue from '../../utils/isStandardSyntaxValue.mjs';
 import matchesStringOrRegExp from '../../utils/matchesStringOrRegExp.mjs';
+import mergeSyntaxDefinitions from '../../utils/mergeSyntaxDefinitions.mjs';
 import report from '../../utils/report.mjs';
 import ruleMessages from '../../utils/ruleMessages.mjs';
 import validateObjectWithArrayProps from '../../utils/validateObjectWithArrayProps.mjs';
 import validateObjectWithProps from '../../utils/validateObjectWithProps.mjs';
 import validateOptions from '../../utils/validateOptions.mjs';
 
+/** @todo leverage import attributes once support for Node.js v18.19 is dropped */
+const require = createRequire(import.meta.url);
+const syntaxPatches = require('@csstools/css-syntax-patches-for-csstree/dist/index.json').next;
+
 const ruleName = 'declaration-property-value-no-unknown';
 
 const messages = ruleMessages(ruleName, {
@@ -67,21 +73,7 @@ const rule = (primary, secondaryOptions) => {
 			return Boolean(valuePattern && matchesStringOrRegExp(value, valuePattern));
 		};
 
-		/** @type {SecondaryOptions['propertiesSyntax']} */
-		const propertiesSyntax = {
-			'text-box-edge':
-				'auto | [ text | cap | ex | ideographic | ideographic-ink ] [ text | alphabetic | ideographic | ideographic-ink ]?',
-			'text-box-trim': 'none | trim-start | trim-end | trim-both',
-			'view-timeline':
-				"[ <'view-timeline-name'> [ <'view-timeline-axis'> || <'view-timeline-inset'> ]? ]#",
-			'font-size': '| math',
-			...secondaryOptions?.propertiesSyntax,
-		};
-
-		/**
-		 * @todo add support for oklab(), oklch(), color(), color-mix(), light-dark(), etc.
-		 * @see https://drafts.csswg.org/css-color-5/
-		 */
+		const propertiesSyntax = { ...secondaryOptions?.propertiesSyntax };
 		const typesSyntax = { ...secondaryOptions?.typesSyntax };
 
 		/** @type {Map<string, string>} */
@@ -121,12 +113,13 @@ const rule = (primary, secondaryOptions) => {
 		});
 
 		const languageOptions = result.stylelint.config?.languageOptions;
-		const forkedLexer = fork({
-			atrules: languageOptions?.syntax?.atRules || {},
-			properties: { ...(languageOptions?.syntax?.properties || {}), ...propertiesSyntax },
-			types: { ...(languageOptions?.syntax?.types || {}), ...typesSyntax },
-			cssWideKeywords: languageOptions?.syntax?.cssWideKeywords || [],
-		}).lexer;
+		const forkedLexer = fork(
+			mergeSyntaxDefinitions(
+				syntaxPatches,
+				{ ...languageOptions?.syntax, atrules: languageOptions?.syntax?.atRules },
+				{ properties: propertiesSyntax, types: typesSyntax },
+			),
+		).lexer;
 
 		root.walkDecls((decl) => {
 			const { prop } = decl;