Improve code coverage for cli package (#13724)

packages/cli/src/utils/updateEventEmitter.test.ts

@@ -0,0 +1,22 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect, vi } from 'vitest';
+import { updateEventEmitter } from './updateEventEmitter.js';
+
+describe('updateEventEmitter', () => {
+  it('should allow registering and emitting events', () => {
+    const callback = vi.fn();
+    const eventName = 'test-event';
+
+    updateEventEmitter.on(eventName, callback);
+    updateEventEmitter.emit(eventName, 'test-data');
+
+    expect(callback).toHaveBeenCalledWith('test-data');
+
+    updateEventEmitter.off(eventName, callback);
+  });
+});