findGitRoot function

String? findGitRoot(String startPath)

Find the git root by walking up the directory tree. Looks for a .git directory or file (worktrees/submodules use a file).

Implementation

String? findGitRoot(String startPath) {
  if (_gitRootCache.containsKey(startPath)) return _gitRootCache[startPath];

  var current = p.absolute(startPath);
  final root = p.rootPrefix(current);

  while (true) {
    try {
      final gitPath = p.join(current, '.git');
      final stat = FileStat.statSync(gitPath);
      if (stat.type == FileSystemEntityType.directory ||
          stat.type == FileSystemEntityType.file) {
        _gitRootCache[startPath] = current;
        return current;
      }
    } catch (_) {}

    final parent = p.dirname(current);
    if (parent == current || parent == root) {
      // Check root as well
      try {
        final gitPath = p.join(root, '.git');
        final stat = FileStat.statSync(gitPath);
        if (stat.type == FileSystemEntityType.directory ||
            stat.type == FileSystemEntityType.file) {
          _gitRootCache[startPath] = root;
          return root;
        }
      } catch (_) {}
      break;
    }
    current = parent;
  }

  _gitRootCache[startPath] = null;
  return null;
}