Function installGitSyncHook

src/sync/git-hooks.ts:125–163

(
  projectRoot: string,
  hooks: GitHookName[] = DEFAULT_SYNC_HOOKS,
)

 * it, and any user-authored hook content is preserved.
 */
export function installGitSyncHook(
  projectRoot: string,
  hooks: GitHookName[] = DEFAULT_SYNC_HOOKS,
): GitHookResult {
  const hooksDir = gitHooksDir(projectRoot);
  if (!hooksDir) {
    return { installed: [], hooksDir: null, skipped: 'not a git repository' };
  }

  try {
    fs.mkdirSync(hooksDir, { recursive: true });
  } catch {
    return { installed: [], hooksDir, skipped: 'could not access the git hooks directory' };
  }

  const block = markerBlock();
  const installed: GitHookName[] = [];

  for (const hook of hooks) {
    const file = path.join(hooksDir, hook);
    let content: string;

    if (fs.existsSync(file)) {
      // Strip any prior block, then re-append the current one.
      const base = stripMarkerBlock(fs.readFileSync(file, 'utf8')).replace(/\s*$/, '');
      content = base.length > 0
        ? `${base}\n\n${block}\n`
        : `#!/bin/sh\n${block}\n`;
    } else {
      content = `#!/bin/sh\n${block}\n`;
    }

    fs.writeFileSync(file, content);
    chmodExecutable(file);
    installed.push(hook);
  }

  return { installed, hooksDir };
}

/**
 * Remove the CodeGraph sync hooks. Strips only our marker block; deletes the