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

packages/cli/src/ui/components/messages/ErrorMessage.test.tsx

@@ -0,0 +1,26 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { render } from '../../../test-utils/render.js';
+import { ErrorMessage } from './ErrorMessage.js';
+import { describe, it, expect } from 'vitest';
+
+describe('ErrorMessage', () => {
+  it('renders with the correct prefix and text', () => {
+    const { lastFrame } = render(<ErrorMessage text="Something went wrong" />);
+    const output = lastFrame();
+
+    expect(output).toMatchSnapshot();
+  });
+
+  it('renders multiline error messages', () => {
+    const message = 'Error line 1\nError line 2';
+    const { lastFrame } = render(<ErrorMessage text={message} />);
+    const output = lastFrame();
+
+    expect(output).toMatchSnapshot();
+  });
+});