src/cli/shared/parse-port.ts

export function parsePort(raw: unknown): number | null {
  if (raw === undefined || raw === null) {
    return null;
  }
  const value =
    typeof raw === "string"
      ? raw
      : typeof raw === "number" || typeof raw === "bigint"
        ? raw.toString()
        : null;
  if (value === null) {
    return null;
  }
  const parsed = Number.parseInt(value, 10);
  if (!Number.isFinite(parsed) || parsed <= 0) {
    return null;
  }
  return parsed;
}