deriveRootDomain function

String? deriveRootDomain(
  1. String subdomain
)

Implementation

String? deriveRootDomain(String subdomain) {
  final domainParts = subdomain.split('.');

  if (domainParts.length < 2) {
    return null;
  }

  final secondToLastDotIndex = domainParts.length - 2;
  final rootDomain = domainParts.sublist(secondToLastDotIndex).join('.');

  if (rootDomain.contains('.')) {
    return rootDomain;
  }

  return null;
}