chore(applyChanges): cleanup

packages/react/src/utils/changes.ts

@@ -19,11 +19,11 @@ function applyChanges(changes: any[], elements: any[]): any[] {
   // By storing a map of changes for each element, we can a quick lookup as we
   // iterate over the elements array!
   const changesMap = new Map<any, any[]>();
-  const newItems: any[] = [];
+  const addItemChanges: any[] = [];
 
   for (const change of changes) {
     if (change.type === 'add') {
-      newItems.push(change);
+      addItemChanges.push(change);
       continue;
     } else if (change.type === 'remove' || change.type === 'replace') {
       // For a 'remove' change we can safely ignore any other changes queued for
@@ -74,9 +74,15 @@ function applyChanges(changes: any[], elements: any[]): any[] {
     updatedElements.push(updatedElement);
   }
 
-  if (newItems.length) {
-    newItems.forEach((item) => {
-      updatedElements.splice(item.index, 0, { ...item.item });
+  // we need to wait for all changes to be applied before adding new items
+  // to be able to add them at the correct index
+  if (addItemChanges.length) {
+    addItemChanges.forEach((change) => {
+      if (change.index !== undefined) {
+        updatedElements.splice(change.index, 0, { ...change.item });
+      } else {
+        updatedElements.push({ ...change.item });
+      }
     });
   }