feat(core): experimental in-progress steering hints (1 of 3) (#19008)

packages/cli/src/test-utils/AppRig.test.tsx

@@ -0,0 +1,41 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, afterEach } from 'vitest';
+import { AppRig } from './AppRig.js';
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+
+describe('AppRig', () => {
+  let rig: AppRig | undefined;
+
+  afterEach(async () => {
+    await rig?.unmount();
+  });
+
+  it('should render the app and handle a simple message', async () => {
+    const fakeResponsesPath = path.join(
+      __dirname,
+      'fixtures',
+      'simple.responses',
+    );
+    rig = new AppRig({ fakeResponsesPath });
+    await rig.initialize();
+    rig.render();
+
+    // Wait for initial render
+    await rig.waitForIdle();
+
+    // Type a message
+    await rig.type('Hello');
+    await rig.pressEnter();
+
+    // Wait for model response
+    await rig.waitForOutput('Hello! How can I help you today?');
+  });
+});