diff --git a/apps/ai-game-creator-shell/tests/uiTreeUtils.test.ts b/apps/ai-game-creator-shell/tests/uiTreeUtils.test.ts
new file mode 100644
index 000000000..196077400
--- /dev/null
+++ b/apps/ai-game-creator-shell/tests/uiTreeUtils.test.ts
@@ -0,0 +1,30 @@
+import { describe, expect, it } from 'vitest';
+
+import {
+  countUiNodeDescendants,
+  findUiNode,
+} from '../src/features/ui-editor/treeUtils';
+import type { Node } from '../src/features/ui-editor/types/Node';
+
+function node(id: string, children: Node[] = []): Node {
+  return {
+    id,
+    layout: {} as Node['layout'],
+    metadata: {} as Node['metadata'],
+    components: [],
+    children_display_mode: 'Stack',
+    children,
+  };
+}
+
+describe('ui tree utilities', () => {
+  it('finds a nested node and counts all descendants', () => {
+    const nested = node('nested', [node('leaf')]);
+    const root = node('root', [node('page'), nested]);
+
+    expect(findUiNode(root, 'nested')).toBe(nested);
+    expect(findUiNode(root, 'missing')).toBeNull();
+    expect(countUiNodeDescendants(nested)).toBe(1);
+    expect(countUiNodeDescendants(root)).toBe(3);
+  });
+});