std::optional make_type_field()

in watchman/query/fieldlist.cpp [200:266]

• 60 lines of code
• 20 McCabe index (conditional complexity)

std::optional<json_ref> make_type_field(FileResult* file, const QueryContext*) {
  auto dtype = file->dtype();
  if (dtype.has_value()) {
    switch (*dtype) {
      case DType::Regular:
        return typed_string_to_json("f", W_STRING_UNICODE);
      case DType::Dir:
        return typed_string_to_json("d", W_STRING_UNICODE);
      case DType::Symlink:
        return typed_string_to_json("l", W_STRING_UNICODE);
      case DType::Block:
        return typed_string_to_json("b", W_STRING_UNICODE);
      case DType::Char:
        return typed_string_to_json("c", W_STRING_UNICODE);
      case DType::Fifo:
        return typed_string_to_json("p", W_STRING_UNICODE);
      case DType::Socket:
        return typed_string_to_json("s", W_STRING_UNICODE);
      case DType::Whiteout:
        // Whiteout shouldn't generally be visible to userspace,
        // and we don't have a defined letter code for it, so
        // treat it as "who knows!?"
        return typed_string_to_json("?", W_STRING_UNICODE);
      case DType::Unknown:
      default:
          // Not enough info; fall through and use the full stat data
          ;
    }
  }

  // Bias towards the more common file types first
  auto optionalStat = file->stat();
  if (!optionalStat.has_value()) {
    return std::nullopt;
  }

  auto stat = optionalStat.value();
  if (stat.isFile()) {
    return typed_string_to_json("f", W_STRING_UNICODE);
  }
  if (stat.isDir()) {
    return typed_string_to_json("d", W_STRING_UNICODE);
  }
  if (stat.isSymlink()) {
    return typed_string_to_json("l", W_STRING_UNICODE);
  }
#ifndef _WIN32
  if (S_ISBLK(stat.mode)) {
    return typed_string_to_json("b", W_STRING_UNICODE);
  }
  if (S_ISCHR(stat.mode)) {
    return typed_string_to_json("c", W_STRING_UNICODE);
  }
  if (S_ISFIFO(stat.mode)) {
    return typed_string_to_json("p", W_STRING_UNICODE);
  }
  if (S_ISSOCK(stat.mode)) {
    return typed_string_to_json("s", W_STRING_UNICODE);
  }
#endif
#ifdef S_ISDOOR
  if (S_ISDOOR(stat.mode)) {
    return typed_string_to_json("D", W_STRING_UNICODE);
  }
#endif
  return typed_string_to_json("?", W_STRING_UNICODE);
}