pre-release commit

packages/core/src/services/gitService.ts

@@ -0,0 +1,120 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import * as fs from 'fs/promises';
+import * as path from 'path';
+import * as os from 'os';
+import { isNodeError } from '../utils/errors.js';
+import { exec } from 'node:child_process';
+import { simpleGit, SimpleGit, CheckRepoActions } from 'simple-git';
+import { getProjectHash, GEMINI_DIR } from '../utils/paths.js';
+
+export class GitService {
+  private projectRoot: string;
+
+  constructor(projectRoot: string) {
+    this.projectRoot = path.resolve(projectRoot);
+  }
+
+  private getHistoryDir(): string {
+    const hash = getProjectHash(this.projectRoot);
+    return path.join(os.homedir(), GEMINI_DIR, 'history', hash);
+  }
+
+  async initialize(): Promise<void> {
+    const gitAvailable = await this.verifyGitAvailability();
+    if (!gitAvailable) {
+      throw new Error(
+        'Checkpointing is enabled, but Git is not installed. Please install Git or disable checkpointing to continue.',
+      );
+    }
+    this.setupShadowGitRepository();
+  }
+
+  verifyGitAvailability(): Promise<boolean> {
+    return new Promise((resolve) => {
+      exec('git --version', (error) => {
+        if (error) {
+          resolve(false);
+        } else {
+          resolve(true);
+        }
+      });
+    });
+  }
+
+  /**
+   * Creates a hidden git repository in the project root.
+   * The Git repository is used to support checkpointing.
+   */
+  async setupShadowGitRepository() {
+    const repoDir = this.getHistoryDir();
+    const gitConfigPath = path.join(repoDir, '.gitconfig');
+
+    await fs.mkdir(repoDir, { recursive: true });
+
+    // We don't want to inherit the user's name, email, or gpg signing
+    // preferences for the shadow repository, so we create a dedicated gitconfig.
+    const gitConfigContent =
+      '[user]\n  name = Gemini CLI\n  email = gemini-cli@google.com\n[commit]\n  gpgsign = false\n';
+    await fs.writeFile(gitConfigPath, gitConfigContent);
+
+    const repo = simpleGit(repoDir);
+    const isRepoDefined = await repo.checkIsRepo(CheckRepoActions.IS_REPO_ROOT);
+
+    if (!isRepoDefined) {
+      await repo.init(false, {
+        '--initial-branch': 'main',
+      });
+
+      await repo.commit('Initial commit', { '--allow-empty': null });
+    }
+
+    const userGitIgnorePath = path.join(this.projectRoot, '.gitignore');
+    const shadowGitIgnorePath = path.join(repoDir, '.gitignore');
+
+    let userGitIgnoreContent = '';
+    try {
+      userGitIgnoreContent = await fs.readFile(userGitIgnorePath, 'utf-8');
+    } catch (error) {
+      if (isNodeError(error) && error.code !== 'ENOENT') {
+        throw error;
+      }
+    }
+
+    await fs.writeFile(shadowGitIgnorePath, userGitIgnoreContent);
+  }
+
+  private get shadowGitRepository(): SimpleGit {
+    const repoDir = this.getHistoryDir();
+    return simpleGit(this.projectRoot).env({
+      GIT_DIR: path.join(repoDir, '.git'),
+      GIT_WORK_TREE: this.projectRoot,
+      // Prevent git from using the user's global git config.
+      HOME: repoDir,
+      XDG_CONFIG_HOME: repoDir,
+    });
+  }
+
+  async getCurrentCommitHash(): Promise<string> {
+    const hash = await this.shadowGitRepository.raw('rev-parse', 'HEAD');
+    return hash.trim();
+  }
+
+  async createFileSnapshot(message: string): Promise<string> {
+    const repo = this.shadowGitRepository;
+    await repo.add('.');
+    const commitResult = await repo.commit(message);
+    return commitResult.commit;
+  }
+
+  async restoreProjectFromSnapshot(commitHash: string): Promise<void> {
+    const repo = this.shadowGitRepository;
+    await repo.raw(['restore', '--source', commitHash, '.']);
+    // Removes any untracked files that were introduced post snapshot.
+    await repo.clean('f', ['-d']);
+  }
+}