Perf: run cpu intensive task with worker

Build/lib/get-gorhill-publicsuffix.js

@@ -30,5 +30,9 @@ const getGorhillPublicSuffix = async () => {
   return gorhill;
 };
 
-const getGorhillPublicSuffixPromise = getGorhillPublicSuffix();
-module.exports.getGorhillPublicSuffixPromise = getGorhillPublicSuffixPromise;
+/** @type {Promise<import('gorhill-publicsuffixlist').default | null>} */
+let gorhillPublicSuffixPromise = null;
+module.exports.getGorhillPublicSuffixPromise = () => {
+  gorhillPublicSuffixPromise ||= getGorhillPublicSuffix();
+  return gorhillPublicSuffixPromise;
+};

Build/lib/is-domain-loose.js

@@ -10,10 +10,10 @@ module.exports.isDomainLoose = (domain) => {
 };
 
 /**
- * @param {string} domain
+ * @param {string | null | undefined} domain
  */
 module.exports.normalizeDomain = (domain) => {
-  if (domain == null) {
+  if (!domain) {
     return null;
   }