feat(ux): Surface internal errors via unified event system (#11803)

packages/cli/src/ui/AppContainer.test.tsx

@@ -15,7 +15,29 @@ import {
 } from 'vitest';
 import { render, cleanup } from 'ink-testing-library';
 import { AppContainer } from './AppContainer.js';
-import { type Config, makeFakeConfig } from '@google/gemini-cli-core';
+import {
+  type Config,
+  makeFakeConfig,
+  CoreEvent,
+  type UserFeedbackPayload,
+} from '@google/gemini-cli-core';
+
+// Mock coreEvents
+const mockCoreEvents = vi.hoisted(() => ({
+  on: vi.fn(),
+  off: vi.fn(),
+  drainFeedbackBacklog: vi.fn(),
+  emit: vi.fn(),
+}));
+
+vi.mock('@google/gemini-cli-core', async (importOriginal) => {
+  const actual =
+    await importOriginal<typeof import('@google/gemini-cli-core')>();
+  return {
+    ...actual,
+    coreEvents: mockCoreEvents,
+  };
+});
 import type { LoadedSettings } from '../config/settings.js';
 import type { InitializationResult } from '../core/initializer.js';
 import { useQuotaAndFallback } from './hooks/useQuotaAndFallback.js';
@@ -1293,4 +1315,73 @@ describe('AppContainer State Management', () => {
       expect(mockCloseModelDialog).toHaveBeenCalled();
     });
   });
+
+  describe('CoreEvents Integration', () => {
+    it('subscribes to UserFeedback and drains backlog on mount', () => {
+      render(
+        <AppContainer
+          config={mockConfig}
+          settings={mockSettings}
+          version="1.0.0"
+          initializationResult={mockInitResult}
+        />,
+      );
+
+      expect(mockCoreEvents.on).toHaveBeenCalledWith(
+        CoreEvent.UserFeedback,
+        expect.any(Function),
+      );
+      expect(mockCoreEvents.drainFeedbackBacklog).toHaveBeenCalledTimes(1);
+    });
+
+    it('unsubscribes from UserFeedback on unmount', () => {
+      const { unmount } = render(
+        <AppContainer
+          config={mockConfig}
+          settings={mockSettings}
+          version="1.0.0"
+          initializationResult={mockInitResult}
+        />,
+      );
+
+      unmount();
+
+      expect(mockCoreEvents.off).toHaveBeenCalledWith(
+        CoreEvent.UserFeedback,
+        expect.any(Function),
+      );
+    });
+
+    it('adds history item when UserFeedback event is received', () => {
+      render(
+        <AppContainer
+          config={mockConfig}
+          settings={mockSettings}
+          version="1.0.0"
+          initializationResult={mockInitResult}
+        />,
+      );
+
+      // Get the registered handler
+      const handler = mockCoreEvents.on.mock.calls.find(
+        (call: unknown[]) => call[0] === CoreEvent.UserFeedback,
+      )?.[1];
+      expect(handler).toBeDefined();
+
+      // Simulate an event
+      const payload: UserFeedbackPayload = {
+        severity: 'error',
+        message: 'Test error message',
+      };
+      handler(payload);
+
+      expect(mockedUseHistory().addItem).toHaveBeenCalledWith(
+        expect.objectContaining({
+          type: 'error',
+          text: 'Test error message',
+        }),
+        expect.any(Number),
+      );
+    });
+  });
 });

packages/cli/src/ui/AppContainer.tsx

@@ -34,6 +34,7 @@ import {
   type IdeInfo,
   type IdeContext,
   type UserTierId,
+  type UserFeedbackPayload,
   DEFAULT_GEMINI_FLASH_MODEL,
   IdeClient,
   ideContextStore,
@@ -44,6 +45,8 @@ import {
   recordExitFail,
   ShellExecutionService,
   debugLogger,
+  coreEvents,
+  CoreEvent,
 } from '@google/gemini-cli-core';
 import { validateAuthMethod } from '../config/auth.js';
 import { loadHierarchicalGeminiMemory } from '../config/config.js';
@@ -1066,6 +1069,53 @@ Logging in with Google... Please restart Gemini CLI to continue.
     stdout,
   ]);
 
+  useEffect(() => {
+    const handleUserFeedback = (payload: UserFeedbackPayload) => {
+      let type: MessageType;
+      switch (payload.severity) {
+        case 'error':
+          type = MessageType.ERROR;
+          break;
+        case 'warning':
+          type = MessageType.WARNING;
+          break;
+        case 'info':
+          type = MessageType.INFO;
+          break;
+        default:
+          throw new Error(
+            `Unexpected severity for user feedback: ${payload.severity}`,
+          );
+      }
+
+      historyManager.addItem(
+        {
+          type,
+          text: payload.message,
+        },
+        Date.now(),
+      );
+
+      // If there is an attached error object, log it to the debug drawer.
+      if (payload.error) {
+        debugLogger.warn(
+          `[Feedback Details for "${payload.message}"]`,
+          payload.error,
+        );
+      }
+    };
+
+    coreEvents.on(CoreEvent.UserFeedback, handleUserFeedback);
+
+    // Flush any messages that happened during startup before this component
+    // mounted.
+    coreEvents.drainFeedbackBacklog();
+
+    return () => {
+      coreEvents.off(CoreEvent.UserFeedback, handleUserFeedback);
+    };
+  }, [historyManager]);
+
   const filteredConsoleMessages = useMemo(() => {
     if (config.getDebugMode()) {
       return consoleMessages;