feat(sync): GitClient — async wrapper for git CLI

얇은 git CLI 래퍼. F6-L2 sync MVP 의 빌딩 블록.

- run/isRepo/hasRemote/addAll/commit/push/currentBranch
- commit() 은 "nothing to commit" 을 changed=false 로 구분 (정상 path)
- 그 외 실패는 throw, exitCode + stderr 보존
- 8 vitest cases — empty file 로 GIT_CONFIG_GLOBAL/SYSTEM 격리

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/main/services/GitClient.ts

@@ -0,0 +1,79 @@
+import { execFile } from 'node:child_process';
+import { promisify } from 'node:util';
+
+const execFileAsync = promisify(execFile);
+
+export interface GitExecResult {
+  stdout: string;
+  stderr: string;
+  exitCode: number;
+}
+
+export interface GitCommitResult {
+  changed: boolean; // false if "nothing to commit"
+  sha: string | null;
+}
+
+export class GitClient {
+  constructor(private cwd: string, private timeoutMs: number = 60_000) {}
+
+  async run(args: string[]): Promise<GitExecResult> {
+    try {
+      const { stdout, stderr } = await execFileAsync(
+        'git',
+        ['-C', this.cwd, ...args],
+        { timeout: this.timeoutMs, maxBuffer: 10 * 1024 * 1024 }
+      );
+      return { stdout, stderr, exitCode: 0 };
+    } catch (e) {
+      const err = e as { stdout?: string; stderr?: string; code?: number };
+      return {
+        stdout: err.stdout ?? '',
+        stderr: err.stderr ?? String(e),
+        exitCode: typeof err.code === 'number' ? err.code : -1
+      };
+    }
+  }
+
+  async isRepo(): Promise<boolean> {
+    const r = await this.run(['rev-parse', '--git-dir']);
+    return r.exitCode === 0;
+  }
+
+  async hasRemote(name: string = 'origin'): Promise<boolean> {
+    const r = await this.run(['remote', 'get-url', name]);
+    return r.exitCode === 0;
+  }
+
+  async addAll(): Promise<void> {
+    const r = await this.run(['add', '-A']);
+    if (r.exitCode !== 0) throw new Error(`git add failed: ${r.stderr}`);
+  }
+
+  async commit(message: string): Promise<GitCommitResult> {
+    // Detect "nothing to commit" via stderr/stdout rather than treating as a thrown error.
+    const r = await this.run(['commit', '-m', message]);
+    if (r.exitCode === 0) {
+      const sha = await this.run(['rev-parse', 'HEAD']);
+      return { changed: true, sha: sha.stdout.trim() };
+    }
+    const blob = (r.stdout + '\n' + r.stderr).toLowerCase();
+    const nothingToCommit = /nothing to commit|nothing added to commit|no changes added to commit/i.test(blob);
+    if (nothingToCommit) {
+      return { changed: false, sha: null };
+    }
+    throw new Error(`git commit failed: ${r.stderr || r.stdout}`);
+  }
+
+  async push(remote: string = 'origin', branch?: string): Promise<void> {
+    const args = branch ? ['push', remote, branch] : ['push', remote];
+    const r = await this.run(args);
+    if (r.exitCode !== 0) throw new Error(`git push failed: ${r.stderr}`);
+  }
+
+  async currentBranch(): Promise<string> {
+    const r = await this.run(['rev-parse', '--abbrev-ref', 'HEAD']);
+    if (r.exitCode !== 0) throw new Error(`git rev-parse failed: ${r.stderr}`);
+    return r.stdout.trim();
+  }
+}

tests/unit/GitClient.test.ts

@@ -0,0 +1,129 @@
+import { describe, it, expect, beforeEach, afterEach } from 'vitest';
+import { mkdtempSync, rmSync, writeFileSync, closeSync, openSync } from 'node:fs';
+import { tmpdir } from 'node:os';
+import { join } from 'node:path';
+import { execFile } from 'node:child_process';
+import { promisify } from 'node:util';
+import { GitClient } from '@main/services/GitClient.js';
+
+const execFileAsync = promisify(execFile);
+
+// Empty file used as GIT_CONFIG_GLOBAL/SYSTEM to isolate from the user's git config.
+let emptyConfigPath: string;
+let emptyConfigDir: string;
+
+function gitEnv(): NodeJS.ProcessEnv {
+  return {
+    ...process.env,
+    GIT_CONFIG_GLOBAL: emptyConfigPath,
+    GIT_CONFIG_SYSTEM: emptyConfigPath,
+    GIT_AUTHOR_NAME: 'Test',
+    GIT_AUTHOR_EMAIL: 'test@inkling.local',
+    GIT_COMMITTER_NAME: 'Test',
+    GIT_COMMITTER_EMAIL: 'test@inkling.local'
+  };
+}
+
+async function initRepo(dir: string) {
+  const env = gitEnv();
+  await execFileAsync('git', ['init', '-b', 'main', dir], { env });
+  await execFileAsync('git', ['-C', dir, 'config', 'user.email', 'test@inkling.local'], { env });
+  await execFileAsync('git', ['-C', dir, 'config', 'user.name', 'Test'], { env });
+  // Initial commit so HEAD exists.
+  writeFileSync(join(dir, 'init.txt'), 'init');
+  await execFileAsync('git', ['-C', dir, 'add', '-A'], { env });
+  await execFileAsync('git', ['-C', dir, 'commit', '-m', 'initial'], { env });
+}
+
+describe('GitClient', () => {
+  let dir: string;
+  let prevEnv: NodeJS.ProcessEnv;
+
+  beforeEach(() => {
+    // Create an empty file for GIT_CONFIG_GLOBAL/SYSTEM to neutralize the user's global git config.
+    emptyConfigDir = mkdtempSync(join(tmpdir(), 'gc-cfg-'));
+    emptyConfigPath = join(emptyConfigDir, 'empty.gitconfig');
+    closeSync(openSync(emptyConfigPath, 'w')); // touch
+    // Stash and replace process.env so child gits inherit isolated config (GitClient uses default env).
+    prevEnv = { ...process.env };
+    Object.assign(process.env, {
+      GIT_CONFIG_GLOBAL: emptyConfigPath,
+      GIT_CONFIG_SYSTEM: emptyConfigPath,
+      GIT_AUTHOR_NAME: 'Test',
+      GIT_AUTHOR_EMAIL: 'test@inkling.local',
+      GIT_COMMITTER_NAME: 'Test',
+      GIT_COMMITTER_EMAIL: 'test@inkling.local'
+    });
+    dir = mkdtempSync(join(tmpdir(), 'gc-'));
+  });
+
+  afterEach(() => {
+    rmSync(dir, { recursive: true, force: true });
+    rmSync(emptyConfigDir, { recursive: true, force: true });
+    // Restore env exactly.
+    for (const k of Object.keys(process.env)) delete process.env[k];
+    Object.assign(process.env, prevEnv);
+  });
+
+  it('isRepo returns false when dir is not a repo', async () => {
+    const g = new GitClient(dir);
+    expect(await g.isRepo()).toBe(false);
+  });
+
+  it('isRepo returns true after git init', async () => {
+    await initRepo(dir);
+    const g = new GitClient(dir);
+    expect(await g.isRepo()).toBe(true);
+  });
+
+  it('hasRemote returns false when no remote', async () => {
+    await initRepo(dir);
+    const g = new GitClient(dir);
+    expect(await g.hasRemote()).toBe(false);
+  });
+
+  it('hasRemote returns true after remote add', async () => {
+    await initRepo(dir);
+    const remoteDir = mkdtempSync(join(tmpdir(), 'gc-remote-'));
+    try {
+      await execFileAsync('git', ['init', '--bare', remoteDir], { env: gitEnv() });
+      await execFileAsync('git', ['-C', dir, 'remote', 'add', 'origin', remoteDir], { env: gitEnv() });
+      const g = new GitClient(dir);
+      expect(await g.hasRemote()).toBe(true);
+    } finally {
+      rmSync(remoteDir, { recursive: true, force: true });
+    }
+  });
+
+  it('commit returns changed=false when nothing to commit', async () => {
+    await initRepo(dir);
+    const g = new GitClient(dir);
+    const r = await g.commit('test');
+    expect(r.changed).toBe(false);
+    expect(r.sha).toBeNull();
+  });
+
+  it('commit returns changed=true with sha when something to commit', async () => {
+    await initRepo(dir);
+    writeFileSync(join(dir, 'new.txt'), 'hi');
+    const g = new GitClient(dir);
+    await g.addAll();
+    const r = await g.commit('test commit');
+    expect(r.changed).toBe(true);
+    expect(r.sha).toMatch(/^[0-9a-f]{40}$/);
+  });
+
+  it('currentBranch returns the branch name', async () => {
+    await initRepo(dir);
+    const g = new GitClient(dir);
+    const branch = await g.currentBranch();
+    expect(branch).toBe('main');
+  });
+
+  it('run returns non-zero exit code without throwing for invalid args', async () => {
+    await initRepo(dir);
+    const g = new GitClient(dir);
+    const r = await g.run(['this-is-not-a-real-git-subcommand']);
+    expect(r.exitCode).not.toBe(0);
+  });
+});