feat(cli): support ctrl+d to exit (#878)

Similar to ctrl+c, ctrl+d can now be used to exit the program. To avoid accidental exit, ctrl+d must be pressed twice in relatively quick succession (same as ctrl+c).

Following common UX pattern, ctrl+d will be ignored when the input prompt is non-empty. This behavior is similar to how most shell (bash/zsh) behaves. To support this, I had to refactor so that text buffer is initialized outside of the InputPrompt component and instead do it on the main App component to allow input controller to have access to check the content of the text buffer.

2 files changed, 85 insertions, 72 deletions

diff --git a/packages/cli/src/ui/App.tsx b/packages/cli/src/ui/App.tsx
index c7ed9a81..c022fb31 100644
--- a/packages/cli/src/ui/App.tsx
+++ b/packages/cli/src/ui/App.tsx
@@ -11,6 +11,7 @@ import {
   measureElement,
   Static,
   Text,
+  useStdin,
   useInput,
   type Key as InkKeyType,
 } from 'ink';
@@ -54,8 +55,10 @@ import { useLogger } from './hooks/useLogger.js';
 import { StreamingContext } from './contexts/StreamingContext.js';
 import { SessionStatsProvider } from './contexts/SessionContext.js';
 import { useGitBranchName } from './hooks/useGitBranchName.js';
+import { useTextBuffer } from './components/shared/text-buffer.js';
+import * as fs from 'fs';
 
-const CTRL_C_PROMPT_DURATION_MS = 1000;
+const CTRL_EXIT_PROMPT_DURATION_MS = 1000;
 
 interface AppProps {
   config: Config;
@@ -98,6 +101,8 @@ const App = ({ config, settings, startupWarnings = [] }: AppProps) => {
     HistoryItem[] | null
   >(null);
   const ctrlCTimerRef = useRef<NodeJS.Timeout | null>(null);
+  const [ctrlDPressedOnce, setCtrlDPressedOnce] = useState(false);
+  const ctrlDTimerRef = useRef<NodeJS.Timeout | null>(null);
 
   const errorCount = useMemo(
     () => consoleMessages.filter((msg) => msg.type === 'error').length,
@@ -181,54 +186,84 @@ const App = ({ config, settings, startupWarnings = [] }: AppProps) => {
     setQuittingMessages,
   );
 
+  const { rows: terminalHeight, columns: terminalWidth } = useTerminalSize();
+  const { stdin, setRawMode } = useStdin();
+  const isValidPath = useCallback((filePath: string): boolean => {
+    try {
+      return fs.existsSync(filePath) && fs.statSync(filePath).isFile();
+    } catch (_e) {
+      return false;
+    }
+  }, []);
+
+  const widthFraction = 0.9;
+  const inputWidth = Math.max(
+    20,
+    Math.round(terminalWidth * widthFraction) - 3,
+  );
+  const suggestionsWidth = Math.max(60, Math.floor(terminalWidth * 0.8));
+
+  const buffer = useTextBuffer({
+    initialText: '',
+    viewport: { height: 10, width: inputWidth },
+    stdin,
+    setRawMode,
+    isValidPath,
+  });
+
+  const handleExit = useCallback(
+    (
+      pressedOnce: boolean,
+      setPressedOnce: (value: boolean) => void,
+      timerRef: React.MutableRefObject<NodeJS.Timeout | null>,
+    ) => {
+      if (pressedOnce) {
+        if (timerRef.current) {
+          clearTimeout(timerRef.current);
+        }
+        const quitCommand = slashCommands.find(
+          (cmd) => cmd.name === 'quit' || cmd.altName === 'exit',
+        );
+        if (quitCommand) {
+          quitCommand.action('quit', '', '');
+        } else {
+          process.exit(0);
+        }
+      } else {
+        setPressedOnce(true);
+        timerRef.current = setTimeout(() => {
+          setPressedOnce(false);
+          timerRef.current = null;
+        }, CTRL_EXIT_PROMPT_DURATION_MS);
+      }
+    },
+    [slashCommands],
+  );
+
   useInput((input: string, key: InkKeyType) => {
     if (key.ctrl && input === 'o') {
       setShowErrorDetails((prev) => !prev);
       refreshStatic();
     } else if (key.ctrl && input === 't') {
-      // Toggle showing tool descriptions
       const newValue = !showToolDescriptions;
       setShowToolDescriptions(newValue);
       refreshStatic();
 
-      // Re-execute the MCP command to show/hide descriptions
       const mcpServers = config.getMcpServers();
       if (Object.keys(mcpServers || {}).length > 0) {
-        // Pass description flag based on the new value
         handleSlashCommand(newValue ? '/mcp desc' : '/mcp nodesc');
       }
     } else if (key.ctrl && (input === 'c' || input === 'C')) {
-      if (ctrlCPressedOnce) {
-        if (ctrlCTimerRef.current) {
-          clearTimeout(ctrlCTimerRef.current);
-        }
-        const quitCommand = slashCommands.find(
-          (cmd) => cmd.name === 'quit' || cmd.altName === 'exit',
-        );
-        if (quitCommand) {
-          quitCommand.action('quit', '', '');
-        } else {
-          process.exit(0);
-        }
-      } else {
-        setCtrlCPressedOnce(true);
-        ctrlCTimerRef.current = setTimeout(() => {
-          setCtrlCPressedOnce(false);
-          ctrlCTimerRef.current = null;
-        }, CTRL_C_PROMPT_DURATION_MS);
+      handleExit(ctrlCPressedOnce, setCtrlCPressedOnce, ctrlCTimerRef);
+    } else if (key.ctrl && (input === 'd' || input === 'D')) {
+      if (buffer.text.length > 0) {
+        // Do nothing if there is text in the input.
+        return;
       }
+      handleExit(ctrlDPressedOnce, setCtrlDPressedOnce, ctrlDTimerRef);
     }
   });
 
-  useEffect(
-    () => () => {
-      if (ctrlCTimerRef.current) {
-        clearTimeout(ctrlCTimerRef.current);
-      }
-    },
-    [],
-  );
-
   useConsolePatcher({
     onNewMessage: handleNewMessage,
     debugMode: config.getDebugMode(),
@@ -324,7 +359,6 @@ const App = ({ config, settings, startupWarnings = [] }: AppProps) => {
     refreshStatic();
   }, [clearItems, clearConsoleMessagesState, refreshStatic]);
 
-  const { rows: terminalHeight, columns: terminalWidth } = useTerminalSize(); // Get terminalWidth
   const mainControlsRef = useRef<DOMElement>(null);
   const pendingHistoryItemRef = useRef<DOMElement>(null);
 
@@ -514,6 +548,10 @@ const App = ({ config, settings, startupWarnings = [] }: AppProps) => {
                     <Text color={Colors.AccentYellow}>
                       Press Ctrl+C again to exit.
                     </Text>
+                  ) : ctrlDPressedOnce ? (
+                    <Text color={Colors.AccentYellow}>
+                      Press Ctrl+D again to exit.
+                    </Text>
                   ) : (
                     <ContextSummaryDisplay
                       geminiMdFileCount={geminiMdFileCount}
@@ -540,7 +578,9 @@ const App = ({ config, settings, startupWarnings = [] }: AppProps) => {
 
               {isInputActive && (
                 <InputPrompt
-                  widthFraction={0.9}
+                  buffer={buffer}
+                  inputWidth={inputWidth}
+                  suggestionsWidth={suggestionsWidth}
                   onSubmit={handleFinalSubmit}
                   userMessages={userMessages}
                   onClearScreen={handleClearScreen}
diff --git a/packages/cli/src/ui/components/InputPrompt.tsx b/packages/cli/src/ui/components/InputPrompt.tsx
index 534d7112..c4177c00 100644
--- a/packages/cli/src/ui/components/InputPrompt.tsx
+++ b/packages/cli/src/ui/components/InputPrompt.tsx
@@ -4,15 +4,13 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-import * as fs from 'fs';
 import React, { useCallback, useEffect, useState } from 'react';
-import { Text, Box, useInput, useStdin } from 'ink';
+import { Text, Box, useInput } from 'ink';
 import { Colors } from '../colors.js';
 import { SuggestionsDisplay } from './SuggestionsDisplay.js';
 import { useInputHistory } from '../hooks/useInputHistory.js';
-import { useTextBuffer, cpSlice, cpLen } from './shared/text-buffer.js';
+import { cpSlice, cpLen, TextBuffer } from './shared/text-buffer.js';
 import chalk from 'chalk';
-import { useTerminalSize } from '../hooks/useTerminalSize.js';
 import stringWidth from 'string-width';
 import process from 'node:process';
 import { useCompletion } from '../hooks/useCompletion.js';
@@ -21,60 +19,36 @@ import { SlashCommand } from '../hooks/slashCommandProcessor.js';
 import { Config } from '@gemini-cli/core';
 
 export interface InputPromptProps {
+  buffer: TextBuffer;
   onSubmit: (value: string) => void;
   userMessages: readonly string[];
   onClearScreen: () => void;
   config: Config; // Added config for useCompletion
   slashCommands: SlashCommand[]; // Added slashCommands for useCompletion
   placeholder?: string;
-  height?: number; // Visible height of the editor area
   focus?: boolean;
-  widthFraction: number;
+  inputWidth: number;
+  suggestionsWidth: number;
   shellModeActive: boolean;
   setShellModeActive: (value: boolean) => void;
 }
 
 export const InputPrompt: React.FC<InputPromptProps> = ({
+  buffer,
   onSubmit,
   userMessages,
   onClearScreen,
   config,
   slashCommands,
   placeholder = '  Type your message or @path/to/file',
-  height = 10,
   focus = true,
-  widthFraction,
+  inputWidth,
+  suggestionsWidth,
   shellModeActive,
   setShellModeActive,
 }) => {
-  const terminalSize = useTerminalSize();
-  const padding = 3;
-  const effectiveWidth = Math.max(
-    20,
-    Math.round(terminalSize.columns * widthFraction) - padding,
-  );
-  const suggestionsWidth = Math.max(60, Math.floor(terminalSize.columns * 0.8));
-
   const [justNavigatedHistory, setJustNavigatedHistory] = useState(false);
 
-  const { stdin, setRawMode } = useStdin();
-
-  const isValidPath = useCallback((filePath: string): boolean => {
-    try {
-      return fs.existsSync(filePath) && fs.statSync(filePath).isFile();
-    } catch (_e) {
-      return false;
-    }
-  }, []);
-
-  const buffer = useTextBuffer({
-    initialText: '',
-    viewport: { height, width: effectiveWidth },
-    stdin,
-    setRawMode,
-    isValidPath,
-  });
-
   const completion = useCompletion(
     buffer.text,
     config.getTargetDir(),
@@ -370,11 +344,10 @@ export const InputPrompt: React.FC<InputPromptProps> = ({
           ) : (
             linesToRender.map((lineText, visualIdxInRenderedSet) => {
               const cursorVisualRow = cursorVisualRowAbsolute - scrollVisualRow;
-              let display = cpSlice(lineText, 0, effectiveWidth);
+              let display = cpSlice(lineText, 0, inputWidth);
               const currentVisualWidth = stringWidth(display);
-              if (currentVisualWidth < effectiveWidth) {
-                display =
-                  display + ' '.repeat(effectiveWidth - currentVisualWidth);
+              if (currentVisualWidth < inputWidth) {
+                display = display + ' '.repeat(inputWidth - currentVisualWidth);
               }
 
               if (visualIdxInRenderedSet === cursorVisualRow) {
@@ -394,7 +367,7 @@ export const InputPrompt: React.FC<InputPromptProps> = ({
                       cpSlice(display, relativeVisualColForHighlight + 1);
                   } else if (
                     relativeVisualColForHighlight === cpLen(display) &&
-                    cpLen(display) === effectiveWidth
+                    cpLen(display) === inputWidth
                   ) {
                     display = display + chalk.inverse(' ');
                   }