feat: add declaration-property-value-no-unknown rule

lib/rules/declaration-property-value-no-unknown.d.ts

@@ -0,0 +1,31 @@
+import type { CSSPropertiesMap, RuleConfig } from 'stylelint-define-config'
+
+export type DeclarationPropertyValueNoUnknownOptions = RuleConfig<
+  true,
+  {
+    /**
+     * Ignore the specified property and value pairs.
+     * Keys in the object indicate property names.
+     * If a string in the object is surrounded with `"/"`,
+     * it's interpreted as a regular expression.
+     *
+     * For example, `"/.+/"` matches any strings.
+     */
+    ignoreProperties?: Record<CSSPropertiesMap, (string | RegExp)[] | string | RegExp>
+    /**
+     * Extend or alter the properties syntax dictionary.
+     * [CSS Value Definition Syntax](https://github.com/csstree/csstree/blob/master/docs/definition-syntax.md) is used to define a value's syntax.
+     * If a definition starts with `|` it is added to the [existing definition value](https://csstree.github.io/docs/syntax/) if any.
+     */
+    propertiesSyntax?: Record<CSSPropertiesMap, string>
+
+    /**
+     * Extend or alter the types syntax dictionary.
+     * [CSS Value Definition Syntax](https://github.com/csstree/csstree/blob/master/docs/definition-syntax.md) is used to define a value's syntax.
+     * If a definition starts with `|` it is added to the [existing definition value](https://csstree.github.io/docs/syntax/) if any.
+     *
+     * Types are something like a preset which allows you to reuse a definition across other definitions. So, you'll likely want to also use the `propertiesSyntax` option when using this option.
+     */
+    typesSyntax?: Record<string, string>
+  }
+>

lib/types.d.ts

@@ -68,6 +68,7 @@ import type { AtImportPartialExtensionAllowedListOptions } from './rules/at-impo
 import type { AtImportPartialExtensionDisallowedListOptions } from './rules/at-import-partial-extension-disallowed-list'
 import type { AtMixinNoRiskyNestingSelectorOptions } from './rules/at-mixin-no-risky-nesting-selector'
 import type { LoadPartialExtensionOptions } from './rules/load-partial-extension'
+import type { DeclarationPropertyValueNoUnknownOptions } from './rules/declaration-property-value-no-unknown'
 
 export interface Extends {
   'stylelint-config-standard-scss': void
@@ -396,6 +397,27 @@ interface RuleOptions {
    */
   'scss/declaration-nested-properties': DeclarationNestedPropertiesOptions
 
+  /**
+   * Disallow unknown values for properties within declarations.
+   *
+   * This rule considers values for properties defined within the CSS specifications to be known. You can use the `propertiesSyntax` and `typesSyntax` secondary options to extend the syntax.
+   *
+   * This rule is only appropriate for CSS. You should not turn it on for CSS-like languages, such as Sass or Less, as they have their own syntaxes.
+   *
+   * This rule is experimental with some false negatives that we'll patch in minor releases.
+   *
+   * It sometimes overlaps with:
+   * - [`color-no-invalid-hex`](https://github.com/stylelint-scss/stylelint-scss/blob/master/src/rules/color-no-invalid-hex/README.md)
+   * - [`function-no-unknown`](https://github.com/stylelint-scss/stylelint-scss/blob/master/src/rules/function-no-unknown/README.md)
+   * - [`string-no-newline`](https://github.com/stylelint-scss/stylelint-scss/blob/master/src/rules/string-no-newline/README.md)
+   * - [`unit-no-unknown`](https://github.com/stylelint-scss/stylelint-scss/blob/master/src/rules/unit-no-unknown/README.md)
+   *
+   * If duplicate problems are flagged, you can turn off the corresponding rule.
+   *
+   * @see [declaration-property-value-no-unknown](https://github.com/stylelint-scss/stylelint-scss/blob/master/src/rules/declaration-property-value-no-unknown)
+   */
+  'scss/declaration-property-value-no-unknown': DeclarationPropertyValueNoUnknownOptions
+
   /**
    * Disallow `/*`-comments.
    *