Update floating-ui.js - Fix floatingUI arrow() padding

Related to shipshapecode#2302
Arrow function passed through a step's middleware will have a null element, in which case the padding will not be applied. Sum up all such occurrences and pass the final padding to the arrow function with the newly added arrow element.

src/js/utils/floating-ui.js

@@ -187,7 +187,9 @@ export function getFloatingUIOptions(attachToOptions, step) {
     );
 
     if (arrowEl) {
-      options.middleware.push(arrow({ element: arrowEl }));
+      const arrowPadding = getPaddingSum(step.options.floatingUIOptions.middleware || []);
+
+      options.middleware.push(arrow({ element: arrowEl, padding: arrowPadding}));
     }
 
     options.placement = attachToOptions.on;
@@ -207,3 +209,26 @@ function addArrow(step) {
 
   return false;
 }
+
+/**
+ *
+ * @param {Object[]} middleware
+ * @returns {number}
+ */
+function getPaddingSum(middleware) {
+  const arrowFunctions = middleware.filter(isUnusedArrowFunction);
+  let sum = 0;
+  arrowFunctions.forEach((func)=> {
+    sum += func.options.padding;
+  })
+  return sum;
+}
+
+/**
+ *
+ * @param {Object} el
+ * @returns {boolean}
+ */
+function isUnusedArrowFunction(el) {
+  return el.name === "arrow" && el.options.element === null;
+}