Add paint in function types

Fixes jsdom/jsdom#4077.

Regression test: jsdom/jsdom#4078

Author: asamuzaK

lib/utils/propertyDescriptors.js

@@ -40,7 +40,7 @@ function createGenericPropertyDescriptor(property, { caseSensitive, dimensionTyp
               number: numberType,
               percentage: percentageType
             } = dimensionTypes;
-            const { color: colorType, image: imageType } = functionTypes;
+            const { color: colorType, image: imageType, paint: paintType } = functionTypes;
             const [{ name, type, value: itemValue }] = parsedValue;
             switch (type) {
               case AST_TYPES.CALC: {
@@ -111,7 +111,7 @@ function createGenericPropertyDescriptor(property, { caseSensitive, dimensionTyp
               }
               case AST_TYPES.FUNCTION:
               default: {
-                if (colorType) {
+                if (colorType || paintType) {
                   this._setProperty(property, parsers.serializeColor(parsedValue), priority);
                 } else if (imageType) {
                   this._setProperty(property, parsers.serializeGradient(parsedValue), priority);

scripts/prepare.mjs

@@ -38,7 +38,7 @@ const dimensionTypes = [
   "time",
   "time-percentage"
 ];
-const functionTypes = ["color", "image"];
+const functionTypes = ["color", "image", "paint"];
 const typeList = new Set([...caseSensitiveTypes, ...dimensionTypes, ...functionTypes]);
 
 await Promise.all([generateDefinitions(), generateDescriptors()]);