feat: shell history (#1169)

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

@@ -0,0 +1,104 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { useState, useEffect, useCallback } from 'react';
+import * as fs from 'fs/promises';
+import * as path from 'path';
+import { isNodeError } from '@gemini-cli/core';
+
+const HISTORY_DIR = '.gemini';
+const HISTORY_FILE = 'shell_history';
+const MAX_HISTORY_LENGTH = 100;
+
+async function getHistoryFilePath(projectRoot: string): Promise<string> {
+  const historyDir = path.join(projectRoot, HISTORY_DIR);
+  return path.join(historyDir, HISTORY_FILE);
+}
+
+async function readHistoryFile(filePath: string): Promise<string[]> {
+  try {
+    const content = await fs.readFile(filePath, 'utf-8');
+    return content.split('\n').filter(Boolean);
+  } catch (error) {
+    if (isNodeError(error) && error.code === 'ENOENT') {
+      return [];
+    }
+    console.error('Error reading shell history:', error);
+    return [];
+  }
+}
+
+async function writeHistoryFile(
+  filePath: string,
+  history: string[],
+): Promise<void> {
+  try {
+    await fs.mkdir(path.dirname(filePath), { recursive: true });
+    await fs.writeFile(filePath, history.join('\n'));
+  } catch (error) {
+    console.error('Error writing shell history:', error);
+  }
+}
+
+export function useShellHistory(projectRoot: string) {
+  const [history, setHistory] = useState<string[]>([]);
+  const [historyIndex, setHistoryIndex] = useState(-1);
+  const [historyFilePath, setHistoryFilePath] = useState<string | null>(null);
+
+  useEffect(() => {
+    async function loadHistory() {
+      const filePath = await getHistoryFilePath(projectRoot);
+      setHistoryFilePath(filePath);
+      const loadedHistory = await readHistoryFile(filePath);
+      setHistory(loadedHistory.reverse()); // Newest first
+    }
+    loadHistory();
+  }, [projectRoot]);
+
+  const addCommandToHistory = useCallback(
+    (command: string) => {
+      if (!command.trim() || !historyFilePath) {
+        return;
+      }
+      const newHistory = [command, ...history.filter((c) => c !== command)]
+        .slice(0, MAX_HISTORY_LENGTH)
+        .filter(Boolean);
+      setHistory(newHistory);
+      // Write to file in reverse order (oldest first)
+      writeHistoryFile(historyFilePath, [...newHistory].reverse());
+      setHistoryIndex(-1);
+    },
+    [history, historyFilePath],
+  );
+
+  const getPreviousCommand = useCallback(() => {
+    if (history.length === 0) {
+      return null;
+    }
+    const newIndex = Math.min(historyIndex + 1, history.length - 1);
+    setHistoryIndex(newIndex);
+    return history[newIndex] ?? null;
+  }, [history, historyIndex]);
+
+  const getNextCommand = useCallback(() => {
+    if (historyIndex < 0) {
+      return null;
+    }
+    const newIndex = historyIndex - 1;
+    setHistoryIndex(newIndex);
+    if (newIndex < 0) {
+      return '';
+    }
+    return history[newIndex] ?? null;
+  }, [history, historyIndex]);
+
+  return {
+    addCommandToHistory,
+    getPreviousCommand,
+    getNextCommand,
+    resetHistoryPosition: () => setHistoryIndex(-1),
+  };
+}