fix(whois): improve type safety and harden WHOIS parsing for missing fields

test/test.node.ts

@@ -38,6 +38,8 @@ tap.test('should check for a valid tld', async () => {
   const comIsValid = await testSmartWhois.isValidTld('.com');
   console.log(comIsValid);
   expect(comIsValid).toBeTrue();
-})
+});
 
-tap.start();
+export default tap.start({
+  throwOnError: true
+});