Better error handling. (#1150)

components/cart/edit-item-quantity-button.tsx

@@ -32,8 +32,8 @@ export default function EditItemQuantityButton({
                 });
 
           if (error) {
-            alert(error);
-            return;
+            // Trigger the error boundary in the root error.js
+            throw new Error(error.toString());
           }
 
           router.refresh();