Issue #3484065 by grimreaper, pdureau: Carousel item: only add active on the first item.

components/carousel/js/carousel.js

 ((Drupal, once) => {
-  Drupal.ui_suite_bootstrap_carousel =
-    Drupal.ui_suite_bootstrap_carousel || {};
+  Drupal.ui_suite_bootstrap_carousel = Drupal.ui_suite_bootstrap_carousel || {};
 
   /**
-   * Set active class.
+   * Set active class on the first item.
    *
    * @type {Drupal~behavior}
    *
@@ -12,31 +11,14 @@
    */
   Drupal.behaviors.ui_suite_bootstrap_carousel = {
     attach(context) {
-      once(
-        'carousel-active',
-        ".carousel",
-        context,
-      ).forEach((carousel) => {
-        const items = carousel.querySelectorAll('.carousel-inner .carousel-item');
+      once('carousel-active', '.carousel', context).forEach((carousel) => {
+        const items = carousel.querySelectorAll(
+          '.carousel-inner .carousel-item',
+        );
         if (items.length === 0) {
           return;
         }
 
-        // Check if there is an item with the active class.
-        let activeFound = false;
-        items.forEach(function(item) {
-          if (activeFound) {
-            return;
-          }
-          activeFound = item.classList.contains('active');
-        });
-
-        if (activeFound) {
-          return;
-        }
-
-        // If the carousel have no active items, put the active class on the
-        // first one.
         items.item(0).classList.add('active');
       });
     },