fix(Dropdown): set index correctly (#3138)

Author: rivka-ungar

packages/core/src/components/BaseListItem/BaseListItem.types.ts

@@ -83,6 +83,10 @@ export type BaseListItemData<Item = Record<string, unknown>> = Item & {
    * The color of the chip when displayed in multi-select mode.
    */
   chipColor?: ChipsProps["color"];
+  /**
+   * The index of the item in the list.
+   */
+  index?: number;
 };
 
 export type SideElement =

packages/core/src/components/next/Dropdown/utils/dropdownUtils.ts

@@ -25,7 +25,10 @@ export function normalizeOptions<Item extends BaseListItemData>(
             }
             return matchesFilter;
           })
-          .map(item => ({ ...item, index: indexCounter++ }));
+          .map(item => {
+            item.index = indexCounter++;
+            return item;
+          });
 
         return filteredGroupOptions.length > 0 ? [{ ...group, options: filteredGroupOptions }] : [];
       })
@@ -40,7 +43,10 @@ export function normalizeOptions<Item extends BaseListItemData>(
               }
               return matchesFilter;
             })
-            .map(item => ({ ...item, index: indexCounter++ }))
+            .map(item => {
+              item.index = indexCounter++;
+              return item;
+            })
         }
       ];
 }