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

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

@@ -0,0 +1,117 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { act } from 'react';
+import { render } from '../../test-utils/render.js';
+import { ConfigInitDisplay } from './ConfigInitDisplay.js';
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
+import { AppEvent } from '../../utils/events.js';
+import { MCPServerStatus, type McpClient } from '@google/gemini-cli-core';
+import { Text } from 'ink';
+
+// Mock GeminiSpinner
+vi.mock('./GeminiRespondingSpinner.js', () => ({
+  GeminiSpinner: () => <Text>Spinner</Text>,
+}));
+
+// Mock appEvents
+const { mockOn, mockOff, mockEmit } = vi.hoisted(() => ({
+  mockOn: vi.fn(),
+  mockOff: vi.fn(),
+  mockEmit: vi.fn(),
+}));
+
+vi.mock('../../utils/events.js', async (importOriginal) => {
+  const actual = await importOriginal<typeof import('../../utils/events.js')>();
+  return {
+    ...actual,
+    appEvents: {
+      on: mockOn,
+      off: mockOff,
+      emit: mockEmit,
+    },
+  };
+});
+
+describe('ConfigInitDisplay', () => {
+  beforeEach(() => {
+    mockOn.mockClear();
+    mockOff.mockClear();
+    mockEmit.mockClear();
+  });
+
+  afterEach(() => {
+    vi.restoreAllMocks();
+  });
+
+  it('renders initial state', () => {
+    const { lastFrame } = render(<ConfigInitDisplay />);
+    expect(lastFrame()).toMatchSnapshot();
+  });
+
+  it('updates message on McpClientUpdate event', async () => {
+    let listener: ((clients?: Map<string, McpClient>) => void) | undefined;
+    mockOn.mockImplementation((event, fn) => {
+      if (event === AppEvent.McpClientUpdate) {
+        listener = fn;
+      }
+    });
+
+    const { lastFrame } = render(<ConfigInitDisplay />);
+
+    // Wait for listener to be registered
+    await vi.waitFor(() => {
+      if (!listener) throw new Error('Listener not registered yet');
+    });
+
+    const mockClient1 = {
+      getStatus: () => MCPServerStatus.CONNECTED,
+    } as McpClient;
+    const mockClient2 = {
+      getStatus: () => MCPServerStatus.CONNECTING,
+    } as McpClient;
+    const clients = new Map<string, McpClient>([
+      ['server1', mockClient1],
+      ['server2', mockClient2],
+    ]);
+
+    // Trigger the listener manually since we mocked the event emitter
+    act(() => {
+      listener!(clients);
+    });
+
+    // Wait for the UI to update
+    await vi.waitFor(() => {
+      expect(lastFrame()).toMatchSnapshot();
+    });
+  });
+
+  it('handles empty clients map', async () => {
+    let listener: ((clients?: Map<string, McpClient>) => void) | undefined;
+    mockOn.mockImplementation((event, fn) => {
+      if (event === AppEvent.McpClientUpdate) {
+        listener = fn;
+      }
+    });
+
+    const { lastFrame } = render(<ConfigInitDisplay />);
+
+    await vi.waitFor(() => {
+      if (!listener) throw new Error('Listener not registered yet');
+    });
+
+    if (listener) {
+      const safeListener = listener;
+      act(() => {
+        safeListener(new Map());
+      });
+    }
+
+    await vi.waitFor(() => {
+      expect(lastFrame()).toMatchSnapshot();
+    });
+  });
+});