Refactor border shorthand generators to use default priority

Updated generateBorderLineShorthand, generateBorderPositionShorthand, and generateBorderNameShorthand to use a default parameter for priority instead of reassigning within the function. This simplifies the function signatures and improves code clarity.

Author: asamuzaK

lib/normalize.js

@@ -1062,17 +1062,16 @@ const prepareBorderProperties = (property, value, priority, properties, opt = {}
  *
  * @param {Map} items - The map of collected property items.
  * @param {string} property - The shorthand property name to generate.
- * @param {string} prior - The priority of the property.
+ * @param {string} [priority=""] - The priority of the property.
  * @returns {Array} A key-value pair for the generated property.
  */
-const generateBorderLineShorthand = (items, property, prior) => {
+const generateBorderLineShorthand = (items, property, priority = "") => {
   const values = [];
   for (const [, item] of items) {
     const { value: itemValue } = item;
     values.push(itemValue);
   }
   const value = getPositionValue(values);
-  const priority = prior ? prior : "";
   return [property, createPropertyItem(property, value, priority)];
 };
 
@@ -1081,17 +1080,16 @@ const generateBorderLineShorthand = (items, property, prior) => {
  *
  * @param {Map} items - The map of collected property items.
  * @param {string} property - The shorthand property name to generate.
- * @param {string} prior - The priority of the property.
+ * @param {string} [priority=""] - The priority of the property.
  * @returns {Array} A key-value pair for the generated property.
  */
-const generateBorderPositionShorthand = (items, property, prior) => {
+const generateBorderPositionShorthand = (items, property, priority = "") => {
   const values = [];
   for (const [, item] of items) {
     const { value: itemValue } = item;
     values.push(itemValue);
   }
   const value = values.join(" ");
-  const priority = prior ? prior : "";
   return [property, createPropertyItem(property, value, priority)];
 };
 
@@ -1100,14 +1098,13 @@ const generateBorderPositionShorthand = (items, property, prior) => {
  *
  * @param {Set|Array} items - The collection of property values.
  * @param {string} property - The shorthand property name to generate.
- * @param {string} prior - The priority of the property.
+ * @param {string} [priority=""] - The priority of the property.
  * @returns {Array|undefined} A key-value pair for the generated property or undefined.
  */
-const generateBorderNameShorthand = (items, property, prior) => {
+const generateBorderNameShorthand = (items, property, priority = "") => {
   const values = new Set(items);
   if (values.size === 1) {
     const value = values.keys().next().value;
-    const priority = prior ? prior : "";
     return [property, createPropertyItem(property, value, priority)];
   }
 };