Refactor longhand property updates into helper function

Introduces the updateLonghandProperties helper to consolidate logic for updating longhand properties in multiple places. This reduces code duplication and improves maintainability in normalize.js.

Author: asamuzaK

lib/normalize.js

@@ -1303,7 +1303,6 @@ const updatePositionLonghands = (properties, namePart, linePart, value, priority
     const longhandProperty = `${namePart}-${position}-${linePart}`;
     const longhandValue = Array.isArray(value) ? getPositionValue(value, position) : value;
     const longhandItem = createPropertyItem(longhandProperty, longhandValue, priority);
-
     if (properties.has(longhandProperty)) {
       const { priority: existingPriority } = properties.get(longhandProperty);
       if (!existingPriority) {
@@ -1316,6 +1315,30 @@ const updatePositionLonghands = (properties, namePart, linePart, value, priority
   }
 };
 
+/**
+ * Updates longhand properties based on a values object.
+ *
+ * @param {Map} properties - The map of properties to update.
+ * @param {Object} values - The object containing property keys and values.
+ * @param {string} priority - The priority of the properties.
+ * @param {boolean} [safe=false] - Whether to preserve existing priority.
+ */
+const updateLonghandProperties = (properties, values, priority, safe = false) => {
+  for (const property of Object.keys(values)) {
+    const value = values[property];
+    const item = createPropertyItem(property, value, priority);
+    if (safe && properties.has(property)) {
+      const { priority: existingPriority } = properties.get(property);
+      if (!existingPriority) {
+        properties.delete(property);
+        properties.set(property, item);
+      }
+    } else {
+      properties.set(property, item);
+    }
+  }
+};
+
 /**
  * Processes border properties from the borders map, expanding and normalizing them.
  *
@@ -1372,19 +1395,7 @@ const processBorderProperties = (borders, parseOpt) => {
               parsedItem[key] = initialValue;
             }
           }
-          for (const longhandProperty of Object.keys(parsedItem)) {
-            const longhandValue = parsedItem[longhandProperty];
-            const longhandItem = createPropertyItem(longhandProperty, longhandValue, priority);
-            if (longhandProperties.has(longhandProperty)) {
-              const { priority: longhandPriority } = longhandProperties.get(longhandProperty);
-              if (!longhandPriority) {
-                longhandProperties.delete(longhandProperty);
-                longhandProperties.set(longhandProperty, longhandItem);
-              }
-            } else {
-              longhandProperties.set(longhandProperty, longhandItem);
-            }
-          }
+          updateLonghandProperties(longhandProperties, parsedItem, priority, true);
         }
       }
     } else if (longhandProperties.has(property)) {
@@ -1465,22 +1476,10 @@ const prepareProperties = (properties, opt = {}) => {
             );
           }
         } else if (parsedValue) {
-          for (const longhandProperty of Object.keys(parsedValue)) {
-            const longhandValue = parsedValue[longhandProperty];
-            parsedProperties.set(
-              longhandProperty,
-              createPropertyItem(longhandProperty, longhandValue, priority)
-            );
-          }
+          updateLonghandProperties(parsedProperties, parsedValue, priority);
         }
       } else if (parsedValues && typeof parsedValues !== "string") {
-        for (const longhandProperty of Object.keys(parsedValues)) {
-          const longhandValue = parsedValues[longhandProperty];
-          parsedProperties.set(
-            longhandProperty,
-            createPropertyItem(longhandProperty, longhandValue, priority)
-          );
-        }
+        updateLonghandProperties(parsedProperties, parsedValues, priority);
       }
       if (!omitShorthandProperty) {
         if (property === BACKGROUND) {