Improve test coverage for cli/src/ui/components (#13598)

packages/cli/src/ui/components/CopyModeWarning.test.tsx

@@ -0,0 +1,37 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { render } from '../../test-utils/render.js';
+import { CopyModeWarning } from './CopyModeWarning.js';
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import { useUIState, type UIState } from '../contexts/UIStateContext.js';
+
+vi.mock('../contexts/UIStateContext.js');
+
+describe('CopyModeWarning', () => {
+  const mockUseUIState = vi.mocked(useUIState);
+
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it('renders nothing when copy mode is disabled', () => {
+    mockUseUIState.mockReturnValue({
+      copyModeEnabled: false,
+    } as unknown as UIState);
+    const { lastFrame } = render(<CopyModeWarning />);
+    expect(lastFrame()).toBe('');
+  });
+
+  it('renders warning when copy mode is enabled', () => {
+    mockUseUIState.mockReturnValue({
+      copyModeEnabled: true,
+    } as unknown as UIState);
+    const { lastFrame } = render(<CopyModeWarning />);
+    expect(lastFrame()).toContain('In Copy Mode');
+    expect(lastFrame()).toContain('Press any key to exit');
+  });
+});