Fix: add back fastreturn support (#16440)

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

@@ -38,6 +38,7 @@ import { createMockCommandContext } from '../../test-utils/mockCommandContext.js
 import stripAnsi from 'strip-ansi';
 import chalk from 'chalk';
 import { StreamingState } from '../types.js';
+import { terminalCapabilityManager } from '../utils/terminalCapabilityManager.js';
 
 vi.mock('../hooks/useShellHistory.js');
 vi.mock('../hooks/useCommandCompletion.js');
@@ -124,6 +125,10 @@ describe('InputPrompt', () => {
 
   beforeEach(() => {
     vi.resetAllMocks();
+    vi.spyOn(
+      terminalCapabilityManager,
+      'isKittyProtocolEnabled',
+    ).mockReturnValue(true);
 
     mockCommandContext = createMockCommandContext();
 

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

@@ -35,9 +35,10 @@ import {
   type SettingDefinition,
   type SettingsSchemaType,
 } from '../../config/settingsSchema.js';
+import { terminalCapabilityManager } from '../utils/terminalCapabilityManager.js';
 
 // Mock the VimModeContext
-const mockToggleVimEnabled = vi.fn();
+const mockToggleVimEnabled = vi.fn().mockResolvedValue(undefined);
 const mockSetVimMode = vi.fn();
 
 vi.mock('../contexts/UIStateContext.js', () => ({
@@ -253,7 +254,12 @@ const renderDialog = (
 
 describe('SettingsDialog', () => {
   beforeEach(() => {
-    mockToggleVimEnabled.mockResolvedValue(true);
+    vi.clearAllMocks();
+    vi.spyOn(
+      terminalCapabilityManager,
+      'isKittyProtocolEnabled',
+    ).mockReturnValue(true);
+    mockToggleVimEnabled.mockRejectedValue(undefined);
   });
 
   afterEach(() => {

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

@@ -16,7 +16,9 @@ import {
   KeypressProvider,
   useKeypressContext,
   ESC_TIMEOUT,
+  FAST_RETURN_TIMEOUT,
 } from './KeypressContext.js';
+import { terminalCapabilityManager } from '../utils/terminalCapabilityManager.js';
 import { useStdin } from 'ink';
 import { EventEmitter } from 'node:events';
 
@@ -154,6 +156,53 @@ describe('KeypressContext', () => {
     );
   });
 
+  describe('Fast return buffering', () => {
+    let kittySpy: ReturnType<typeof vi.spyOn>;
+
+    beforeEach(() => {
+      kittySpy = vi
+        .spyOn(terminalCapabilityManager, 'isKittyProtocolEnabled')
+        .mockReturnValue(false);
+    });
+
+    afterEach(() => kittySpy.mockRestore());
+
+    it('should buffer return key pressed quickly after another key', async () => {
+      const { keyHandler } = setupKeypressTest();
+
+      act(() => stdin.write('a'));
+      expect(keyHandler).toHaveBeenLastCalledWith(
+        expect.objectContaining({ name: 'a' }),
+      );
+
+      act(() => stdin.write('\r'));
+
+      expect(keyHandler).toHaveBeenLastCalledWith(
+        expect.objectContaining({
+          name: '',
+          sequence: '\r',
+          insertable: true,
+        }),
+      );
+    });
+
+    it('should NOT buffer return key if delay is long enough', async () => {
+      const { keyHandler } = setupKeypressTest();
+
+      act(() => stdin.write('a'));
+
+      vi.advanceTimersByTime(FAST_RETURN_TIMEOUT + 1);
+
+      act(() => stdin.write('\r'));
+
+      expect(keyHandler).toHaveBeenLastCalledWith(
+        expect.objectContaining({
+          name: 'return',
+        }),
+      );
+    });
+  });
+
   describe('Escape key handling', () => {
     it('should recognize escape key (keycode 27) in kitty protocol', async () => {
       const { keyHandler } = setupKeypressTest();

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

@@ -19,6 +19,7 @@ import { ESC } from '../utils/input.js';
 import { parseMouseEvent } from '../utils/mouse.js';
 import { FOCUS_IN, FOCUS_OUT } from '../hooks/useFocus.js';
 import { appEvents, AppEvent } from '../../utils/events.js';
+import { terminalCapabilityManager } from '../utils/terminalCapabilityManager.js';
 
 export const BACKSLASH_ENTER_TIMEOUT = 5;
 export const ESC_TIMEOUT = 50;
@@ -143,6 +144,30 @@ function nonKeyboardEventFilter(
   };
 }
 
+/**
+ * Converts return keys pressed quickly after other keys into plain
+ * insertable return characters.
+ *
+ * This is to accommodate older terminals that paste text without bracketing.
+ */
+function bufferFastReturn(keypressHandler: KeypressHandler): KeypressHandler {
+  let lastKeyTime = 0;
+  return (key: Key) => {
+    const now = Date.now();
+    if (key.name === 'return' && now - lastKeyTime <= FAST_RETURN_TIMEOUT) {
+      keypressHandler({
+        ...key,
+        name: '',
+        sequence: '\r',
+        insertable: true,
+      });
+    } else {
+      keypressHandler(key);
+    }
+    lastKeyTime = now;
+  };
+}
+
 /**
  * Buffers "/" keys to see if they are followed return.
  * Will flush the buffer if no data is received for DRAG_COMPLETION_TIMEOUT_MS
@@ -641,6 +666,9 @@ export function KeypressProvider({
     process.stdin.setEncoding('utf8'); // Make data events emit strings
 
     let processor = nonKeyboardEventFilter(broadcast);
+    if (!terminalCapabilityManager.isKittyProtocolEnabled()) {
+      processor = bufferFastReturn(processor);
+    }
     processor = bufferBackslashEnter(processor);
     processor = bufferPaste(processor);
     let dataListener = createDataListener(processor);