feat(sessions): Add automatic session cleanup and retention policy (#7662)

packages/cli/src/utils/sessionUtils.ts

@@ -0,0 +1,120 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import {
+  SESSION_FILE_PREFIX,
+  type ConversationRecord,
+} from '@google/gemini-cli-core';
+import * as fs from 'node:fs/promises';
+import path from 'node:path';
+
+/**
+ * Session information for display and selection purposes.
+ */
+export interface SessionInfo {
+  /** Unique session identifier (filename without .json) */
+  id: string;
+  /** Full filename including .json extension */
+  fileName: string;
+  /** ISO timestamp when session was last updated */
+  lastUpdated: string;
+  /** Whether this is the currently active session */
+  isCurrentSession: boolean;
+}
+
+/**
+ * Represents a session file, which may be valid or corrupted.
+ */
+export interface SessionFileEntry {
+  /** Full filename including .json extension */
+  fileName: string;
+  /** Parsed session info if valid, null if corrupted */
+  sessionInfo: SessionInfo | null;
+}
+
+/**
+ * Loads all session files (including corrupted ones) from the chats directory.
+ * @returns Array of session file entries, with sessionInfo null for corrupted files
+ */
+export const getAllSessionFiles = async (
+  chatsDir: string,
+  currentSessionId?: string,
+): Promise<SessionFileEntry[]> => {
+  try {
+    const files = await fs.readdir(chatsDir);
+    const sessionFiles = files
+      .filter((f) => f.startsWith(SESSION_FILE_PREFIX) && f.endsWith('.json'))
+      .sort(); // Sort by filename, which includes timestamp
+
+    const sessionPromises = sessionFiles.map(
+      async (file): Promise<SessionFileEntry> => {
+        const filePath = path.join(chatsDir, file);
+        try {
+          const content: ConversationRecord = JSON.parse(
+            await fs.readFile(filePath, 'utf8'),
+          );
+
+          // Validate required fields
+          if (
+            !content.sessionId ||
+            !content.messages ||
+            !Array.isArray(content.messages) ||
+            !content.startTime ||
+            !content.lastUpdated
+          ) {
+            // Missing required fields - treat as corrupted
+            return { fileName: file, sessionInfo: null };
+          }
+
+          const isCurrentSession = currentSessionId
+            ? file.includes(currentSessionId.slice(0, 8))
+            : false;
+
+          const sessionInfo: SessionInfo = {
+            id: content.sessionId,
+            fileName: file,
+            lastUpdated: content.lastUpdated,
+            isCurrentSession,
+          };
+
+          return { fileName: file, sessionInfo };
+        } catch {
+          // File is corrupted (can't read or parse JSON)
+          return { fileName: file, sessionInfo: null };
+        }
+      },
+    );
+    return await Promise.all(sessionPromises);
+  } catch (error) {
+    // It's expected that the directory might not exist, which is not an error.
+    if (error instanceof Error && 'code' in error && error.code === 'ENOENT') {
+      return [];
+    }
+    // For other errors (e.g., permissions), re-throw to be handled by the caller.
+    throw error;
+  }
+};
+
+/**
+ * Loads all valid session files from the chats directory and converts them to SessionInfo.
+ * Corrupted files are automatically filtered out.
+ */
+export const getSessionFiles = async (
+  chatsDir: string,
+  currentSessionId?: string,
+): Promise<SessionInfo[]> => {
+  const allFiles = await getAllSessionFiles(chatsDir, currentSessionId);
+
+  // Filter out corrupted files and extract SessionInfo
+  const validSessions = allFiles
+    .filter(
+      (entry): entry is { fileName: string; sessionInfo: SessionInfo } =>
+        entry.sessionInfo !== null,
+    )
+    .map((entry) => entry.sessionInfo);
+
+  return validSessions;
+};