Improve getPropertyDescriptor() fallback code

getPropertyDescriptor() is used for the generic getters and setters that do not have implementations in properties/*.js. Change from just parsing CSS and setting it as-is, to handle properties more correctly by using the AST types.

Author: asamuzaK

lib/utils/propertyDescriptors.js

@@ -2,18 +2,54 @@
 
 const parsers = require("../parsers");
 
-exports.getPropertyDescriptor = function getPropertyDescriptor(property) {
-  return {
-    set(v) {
-      v = parsers.parsePropertyValue(property, v, {
-        globalObject: this._global
+const { AST_TYPES } = parsers;
+
+const getPropertyDescriptor = (property) => ({
+  set(v) {
+    const value = parsers.prepareValue(v, this._global);
+    if (parsers.hasVarFunc(value)) {
+      this._setProperty(property, value);
+    } else {
+      const parsedValue = parsers.parsePropertyValue(property, v, {
+        globalObject: this._global,
+        inArray: true
       });
-      this._setProperty(property, v);
-    },
-    get() {
-      return this.getPropertyValue(property);
-    },
-    enumerable: true,
-    configurable: true
-  };
+      if (Array.isArray(parsedValue)) {
+        if (parsedValue.length === 1) {
+          const [{ name, type, value: itemValue }] = parsedValue;
+          switch (type) {
+            case AST_TYPES.CALC: {
+              this._setProperty(property, `${name}(${itemValue})`);
+              break;
+            }
+            case AST_TYPES.GLOBAL_KEYWORD:
+            case AST_TYPES.IDENTIFIER: {
+              // Set the normalized name for keywords or identifiers.
+              this._setProperty(property, name);
+              break;
+            }
+            default: {
+              // Set the prepared value for Dimension, Function, etc.
+              this._setProperty(property, value);
+            }
+          }
+        } else {
+          // Set the prepared value for lists containing multiple values.
+          this._setProperty(property, value);
+        }
+      } else if (typeof parsedValue === "string") {
+        // Empty string.
+        this._setProperty(property, parsedValue);
+      }
+    }
+  },
+  get() {
+    return this.getPropertyValue(property);
+  },
+  enumerable: true,
+  configurable: true
+});
+
+module.exports = {
+  getPropertyDescriptor
 };