Merge branch 'main' into test-utils-model-fallback

Support model fallbacks in integration tests by allowing a comma-separated list of models via the `GEMINI_MODEL` environment variable or the `model` option in `TestRig.setup()`. This will automatically configure a fallback chain using `dynamicModelConfiguration` with `silent` actions.

Fixes #23568

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

@@ -534,7 +534,6 @@ export const mockAppState: AppState = {
 };
 
 const mockUIActions: UIActions = {
-  toggleAlternateBuffer: vi.fn(),
   handleThemeSelect: vi.fn(),
   closeThemeDialog: vi.fn(),
   handleThemeHighlight: vi.fn(),

packages/cli/src/ui/AppContainer.tsx

@@ -68,10 +68,8 @@ import {
   writeToStdout,
   disableMouseEvents,
   enterAlternateScreen,
-  exitAlternateScreen,
   enableMouseEvents,
   disableLineWrapping,
-  enableLineWrapping,
   shouldEnterAlternateScreen,
   startupProfiler,
   SessionStartSource,
@@ -215,7 +213,7 @@ export const AppContainer = (props: AppContainerProps) => {
   });
 
   useMemoryMonitor(historyManager);
-  const [isAlternateBuffer, setIsAlternateBuffer] = useState(config.getUseAlternateBuffer());
+  const isAlternateBuffer = config.getUseAlternateBuffer();
   const [corgiMode, setCorgiMode] = useState(false);
   const [forceRerenderKey, setForceRerenderKey] = useState(0);
   const [debugMessage, setDebugMessage] = useState<string>('');
@@ -1552,23 +1550,6 @@ Logging in with Google... Restarting Gemini CLI to continue.
     type: TransientMessageType;
   }>(WARNING_PROMPT_DURATION_MS);
 
-  const [shownBufferToggleHint, setShownBufferToggleHint] = useState(false);
-
-  useEffect(() => {
-    if (isAlternateBuffer) return;
-
-    const isLongHistory = historyManager.history.length > 15;
-    const isComplexPrompt = buffer.text.length > 200 || buffer.text.includes('\n');
-
-    if ((isLongHistory || isComplexPrompt) && !shownBufferToggleHint) {
-      showTransientMessage({ 
-        text: 'Tip: Press Alt+T to toggle full-screen mode for better scrolling/editing', 
-        type: TransientMessageType.Hint 
-      });
-      setShownBufferToggleHint(true);
-    }
-  }, [historyManager.history.length, buffer.text, isAlternateBuffer, shownBufferToggleHint, showTransientMessage]);
-
   const {
     isFolderTrustDialogOpen,
     discoveryResults: folderDiscoveryResults,
@@ -1719,11 +1700,6 @@ Logging in with Google... Restarting Gemini CLI to continue.
         return true;
       }
 
-      if (keyMatchers[Command.TOGGLE_BUFFER_MODE](key)) {
-        toggleAlternateBuffer();
-        return true;
-      }
-
       if (keyMatchers[Command.QUIT](key)) {
         // If the user presses Ctrl+C, we want to cancel any ongoing requests.
         // This should happen regardless of the count.
@@ -2228,11 +2204,8 @@ Logging in with Google... Restarting Gemini CLI to continue.
     };
   }, [config, refreshStatic]);
 
-  const showIsAlternateBufferHint = (historyManager.history.length > 15 || buffer.text.length > 200 || buffer.text.includes('\n')) && !isAlternateBuffer;
-
   const uiState: UIState = useMemo(
     () => ({
-      isAlternateBuffer,
       history: historyManager.history,
       historyManager,
       isThemeDialogOpen,
@@ -2358,7 +2331,6 @@ Logging in with Google... Restarting Gemini CLI to continue.
       adminSettingsChanged,
       newAgents,
       showIsExpandableHint,
-      showIsAlternateBufferHint,
       hintMode:
         config.isModelSteeringEnabled() && isToolExecuting(pendingHistoryItems),
       hintBuffer: '',
@@ -2485,8 +2457,6 @@ Logging in with Google... Restarting Gemini CLI to continue.
       adminSettingsChanged,
       newAgents,
       showIsExpandableHint,
-      showIsAlternateBufferHint,
-      isAlternateBuffer,
     ],
   );
 
@@ -2495,31 +2465,6 @@ Logging in with Google... Restarting Gemini CLI to continue.
     [setShowPrivacyNotice],
   );
 
-  const toggleAlternateBuffer = useCallback(() => {
-    setIsAlternateBuffer(prev => {
-      const next = !prev;
-      if (next) {
-        enterAlternateScreen();
-        enableMouseEvents();
-        disableLineWrapping();
-      } else {
-        exitAlternateScreen();
-        disableMouseEvents();
-        enableLineWrapping();
-        writeToStdout('\x1b[2J\x1b[H');
-      }
-      process.stdout.emit('resize');
-
-      // Give a tick for resize to process, then trigger remount to force full redraw
-      setImmediate(() => {
-        refreshStatic();
-        setForceRerenderKey((prev) => prev + 1);
-      });
-
-      return next;
-    });
-  }, [setIsAlternateBuffer, refreshStatic, setForceRerenderKey]);
-
   const uiActions: UIActions = useMemo(
     () => ({
       handleThemeSelect,
@@ -2531,7 +2476,6 @@ Logging in with Google... Restarting Gemini CLI to continue.
       handleEditorSelect,
       exitEditorDialog,
       exitPrivacyNotice,
-      toggleAlternateBuffer,
       closeSettingsDialog,
       closeModelDialog,
       openAgentConfigDialog,
@@ -2670,7 +2614,6 @@ Logging in with Google... Restarting Gemini CLI to continue.
       config,
       historyManager,
       getPreferredEditor,
-      toggleAlternateBuffer,
     ],
   );
 

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

@@ -142,38 +142,4 @@ describe('<StatusRow />', () => {
     await waitUntilReady();
     expect(lastFrame()).toContain('Tip: Test Tip');
   });
-
-  it('renders buffer toggle hint when showIsAlternateBufferHint is true', async () => {
-    (useComposerStatus as Mock).mockReturnValue({
-      isInteractiveShellWaiting: false,
-      showLoadingIndicator: false,
-      showTips: false,
-      showWit: false,
-      modeContentObj: null,
-      showMinimalContext: false,
-    });
-
-    const uiState: Partial<UIState> = {
-      ...defaultUiState,
-      showIsAlternateBufferHint: true,
-    };
-
-    const { lastFrame, waitUntilReady } = await renderWithProviders(
-      <StatusRow
-        showUiDetails={false}
-        isNarrow={false}
-        terminalWidth={100}
-        hideContextSummary={false}
-        hideUiDetailsForSuggestions={false}
-        hasPendingActionRequired={false}
-      />,
-      {
-        width: 100,
-        uiState,
-      },
-    );
-
-    await waitUntilReady();
-    expect(lastFrame()).toContain('[Alt+T] Switch to Full Screen');
-  });
 });

packages/cli/src/ui/components/StatusRow.tsx

@@ -206,12 +206,7 @@ export const StatusRow: React.FC<StatusRowProps> = ({
       return uiState.currentTip;
     }
 
-    // 2. Buffer Toggle Hint
-    if (uiState.showIsAlternateBufferHint) {
-      return '[Alt+T] Switch to Full Screen';
-    }
-
-    // 3. Shortcut Hint (Fallback)
+    // 2. Shortcut Hint (Fallback)
     if (
       settings.merged.ui.showShortcutsHint &&
       !hideUiDetailsForSuggestions &&

packages/cli/src/ui/contexts/KeypressContext.tsx

@@ -205,8 +205,6 @@ const MAC_ALT_KEY_CHARACTER_MAP: Record<string, string> = {
   '\u03A9': 'z', // "Ω" Option+z
   '\u00B8': 'Z', // "¸" Option+Shift+z
   '\u2202': 'd', // "∂" delete word forward
-  '\u2020': 't', // "†" toggle full screen buffer
-  '\u00E5': 'a', // "å" Option+a for alternate buffer
 };
 
 function nonKeyboardEventFilter(

packages/cli/src/ui/contexts/UIActionsContext.tsx

@@ -78,7 +78,6 @@ export interface UIActions {
   setShortcutsHelpVisible: (visible: boolean) => void;
   setCleanUiDetailsVisible: (visible: boolean) => void;
   toggleCleanUiDetailsVisible: () => void;
-  toggleAlternateBuffer: () => void;
   revealCleanUiDetailsTemporarily: (durationMs?: number) => void;
   handleWarning: (message: string) => void;
   setEmbeddedShellFocused: (value: boolean) => void;

packages/cli/src/ui/contexts/UIStateContext.tsx

@@ -118,8 +118,6 @@ export interface UIState {
   isEditorDialogOpen: boolean;
   showPrivacyNotice: boolean;
   corgiMode: boolean;
-  isAlternateBuffer: boolean;
-  showIsAlternateBufferHint: boolean;
   debugMessage: string;
   quittingMessages: HistoryItem[] | null;
   isSettingsDialogOpen: boolean;

packages/cli/src/ui/hooks/useAlternateBuffer.test.ts

@@ -11,47 +11,49 @@ import {
   isAlternateBufferEnabled,
 } from './useAlternateBuffer.js';
 import type { Config } from '@google/gemini-cli-core';
-import { useUIState } from '../contexts/UIStateContext.js';
 
-vi.mock('../contexts/UIStateContext.js');
+vi.mock('../contexts/ConfigContext.js', () => ({
+  useConfig: vi.fn(),
+}));
 
-const mockUseUIState = vi.mocked(useUIState);
+const mockUseConfig = vi.mocked(
+  await import('../contexts/ConfigContext.js').then((m) => m.useConfig),
+);
 
 describe('useAlternateBuffer', () => {
   beforeEach(() => {
     vi.clearAllMocks();
   });
 
-  it('should return false when uiState.isAlternateBuffer is false', async () => {
-    mockUseUIState.mockReturnValue({
-      isAlternateBuffer: false,
-    } as unknown as ReturnType<typeof mockUseUIState>);
+  it('should return false when config.getUseAlternateBuffer returns false', async () => {
+    mockUseConfig.mockReturnValue({
+      getUseAlternateBuffer: () => false,
+    } as unknown as ReturnType<typeof mockUseConfig>);
 
     const { result } = await renderHook(() => useAlternateBuffer());
     expect(result.current).toBe(false);
   });
 
-  it('should return true when uiState.isAlternateBuffer is true', async () => {
-    mockUseUIState.mockReturnValue({
-      isAlternateBuffer: true,
-    } as unknown as ReturnType<typeof mockUseUIState>);
+  it('should return true when config.getUseAlternateBuffer returns true', async () => {
+    mockUseConfig.mockReturnValue({
+      getUseAlternateBuffer: () => true,
+    } as unknown as ReturnType<typeof mockUseConfig>);
 
     const { result } = await renderHook(() => useAlternateBuffer());
     expect(result.current).toBe(true);
   });
 
-  it('should react to state changes', async () => {
-    mockUseUIState.mockReturnValue({
-      isAlternateBuffer: false,
-    } as unknown as ReturnType<typeof mockUseUIState>);
+  it('should return the immutable config value, not react to settings changes', async () => {
+    const mockConfig = {
+      getUseAlternateBuffer: () => true,
+    } as unknown as ReturnType<typeof mockUseConfig>;
+
+    mockUseConfig.mockReturnValue(mockConfig);
 
     const { result, rerender } = await renderHook(() => useAlternateBuffer());
 
-    expect(result.current).toBe(false);
-
-    mockUseUIState.mockReturnValue({
-      isAlternateBuffer: true,
-    } as unknown as ReturnType<typeof mockUseUIState>);
+    // Value should remain true even after rerender
+    expect(result.current).toBe(true);
 
     rerender();
 

packages/cli/src/ui/hooks/useAlternateBuffer.ts

@@ -4,14 +4,14 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-import { useUIState } from '../contexts/UIStateContext.js';
+import { useConfig } from '../contexts/ConfigContext.js';
 import type { Config } from '@google/gemini-cli-core';
 
 export const isAlternateBufferEnabled = (config: Config): boolean =>
   config.getUseAlternateBuffer();
 
-// This is read from UIState so that the UI can toggle dynamically
+// This is read from Config so that the UI reads the same value per application session
 export const useAlternateBuffer = (): boolean => {
-  const uiState = useUIState();
-  return uiState.isAlternateBuffer;
+  const config = useConfig();
+  return isAlternateBufferEnabled(config);
 };

packages/cli/src/ui/key/keyBindings.ts

@@ -95,7 +95,6 @@ export enum Command {
   RESTART_APP = 'app.restart',
   SUSPEND_APP = 'app.suspend',
   SHOW_SHELL_INPUT_UNFOCUS_WARNING = 'app.showShellUnfocusWarning',
-  TOGGLE_BUFFER_MODE = 'app.toggleBufferMode',
 
   // Background Shell Controls
   BACKGROUND_SHELL_ESCAPE = 'background.escape',
@@ -393,7 +392,6 @@ export const defaultKeyBindingConfig: KeyBindingConfig = new Map([
   [Command.RESTART_APP, [new KeyBinding('r'), new KeyBinding('shift+r')]],
   [Command.SUSPEND_APP, [new KeyBinding('ctrl+z')]],
   [Command.SHOW_SHELL_INPUT_UNFOCUS_WARNING, [new KeyBinding('tab')]],
-  [Command.TOGGLE_BUFFER_MODE, [new KeyBinding('alt+a')]],
 
   // Background Shell Controls
   [Command.BACKGROUND_SHELL_ESCAPE, [new KeyBinding('escape')]],
@@ -611,7 +609,6 @@ export const commandDescriptions: Readonly<Record<Command, string>> = {
   [Command.SHOW_IDE_CONTEXT_DETAIL]: 'Show IDE context details.',
   [Command.TOGGLE_MARKDOWN]: 'Toggle Markdown rendering.',
   [Command.TOGGLE_COPY_MODE]: 'Toggle copy mode when in alternate buffer mode.',
-  [Command.TOGGLE_BUFFER_MODE]: 'Toggle between regular and full screen (alternate buffer) mode.',
   [Command.TOGGLE_YOLO]: 'Toggle YOLO (auto-approval) mode for tool calls.',
   [Command.CYCLE_APPROVAL_MODE]:
     'Cycle through approval modes: default (prompt), auto_edit (auto-approve edits), and plan (read-only). Plan mode is skipped when the agent is busy.',

packages/test-utils/src/test-rig.ts

@@ -349,6 +349,7 @@ export class TestRig {
   private _interactiveRuns: InteractiveRun[] = [];
   private _spawnedProcesses: ChildProcess[] = [];
   private _initialized = false;
+  private _modelOverride?: string;
 
   setup(
     testName: string,
@@ -356,9 +357,11 @@ export class TestRig {
       settings?: Record<string, unknown>;
       state?: Record<string, unknown>;
       fakeResponsesPath?: string;
+      model?: string;
     } = {},
   ) {
     this.testName = testName;
+    this._modelOverride = options.model;
     const sanitizedName = sanitizeTestName(testName);
     const testFileDir =
       env['INTEGRATION_TEST_FILE_DIR'] || join(os.tmpdir(), 'gemini-cli-tests');
@@ -430,6 +433,53 @@ export class TestRig {
     // The container mounts the test directory at the same path as the host
     const telemetryPath = join(this.homeDir!, 'telemetry.log'); // Always use home directory for telemetry
 
+    const modelEnv = this._modelOverride || env['GEMINI_MODEL'];
+    const models = modelEnv
+      ? modelEnv.split(',').map((m) => m.trim())
+      : [DEFAULT_GEMINI_MODEL];
+
+    const modelSettings: Record<string, any> = {};
+    if (models.length > 1) {
+      // Setup custom fallback chain for integration tests
+      const chainName = 'integration-test-model';
+      modelSettings['model'] = { name: chainName };
+      modelSettings['experimental'] = { dynamicModelConfiguration: true };
+      modelSettings['modelConfigs'] = {
+        modelDefinitions: {
+          [chainName]: {
+            tier: 'auto',
+            isPreview: true,
+            isVisible: false,
+          },
+        },
+        modelIdResolutions: {
+          [chainName]: {
+            default: models[0],
+          },
+        },
+        modelChains: {
+          [chainName]: models.map((m, i) => ({
+            model: m,
+            isLastResort: i === models.length - 1,
+            actions: {
+              terminal: 'silent',
+              transient: 'silent',
+              not_found: 'silent',
+              unknown: 'silent',
+            },
+            stateTransitions: {
+              terminal: 'terminal',
+              transient: 'terminal',
+              not_found: 'terminal',
+              unknown: 'terminal',
+            },
+          })),
+        },
+      };
+    } else {
+      modelSettings['model'] = { name: models[0] };
+    }
+
     const settings = deepMerge(
       {
         general: {
@@ -454,13 +504,7 @@ export class TestRig {
         ui: {
           useAlternateBuffer: true,
         },
-        ...(env['GEMINI_TEST_TYPE'] === 'integration'
-          ? {
-              model: {
-                name: DEFAULT_GEMINI_MODEL,
-              },
-            }
-          : {}),
+        ...(env['GEMINI_TEST_TYPE'] === 'integration' ? modelSettings : {}),
         sandbox:
           env['GEMINI_SANDBOX'] !== 'false' ? env['GEMINI_SANDBOX'] : false,
         // Don't show the IDE connection dialog when running from VsCode