Fix tests where domain name is needed

src/dns/DMARC.ts

@@ -1,6 +1,7 @@
 import dns from 'dns';
 import Test, { TestParameters, Result } from '../Test';
 import logger from '../logger';
+import getDomain from '../functions/getDomain';
 
 class DMARC extends Test {
   public name = 'DMARC';
@@ -9,7 +10,7 @@ class DMARC extends Test {
     logger.info(`Starting ${this.constructor.name} test...`);
 
     const response: any = await new Promise((resolve, reject) => {
-      dns.resolveTxt(`_dmarc.${(new URL(url).hostname)}`, (err, records) => {
+      dns.resolveTxt(`_dmarc.${getDomain(url)}`, (err, records) => {
         if (err) {
           reject(err);
         }

src/dns/NS.ts

@@ -1,14 +1,15 @@
 import whois from 'whois';
 import Test, { TestParameters, Result } from '../Test';
 import logger from '../logger';
+import getDomain from '../functions/getDomain';
 
 class NS extends Test {
   public name = 'NS';
 
   public async test({ url }: TestParameters): Promise<Result> {
     logger.info(`Starting ${this.constructor.name} test...`);
 
-    const nameServers = await this.getNameServers((new URL(url).hostname));
+    const nameServers = await this.getNameServers(getDomain(url));
 
     return {
       status: 'SUCCESS',

src/dns/RegistrationDate.ts

@@ -1,14 +1,15 @@
 import whois from 'whois';
 import Test, { TestParameters, Result } from '../Test';
 import logger from '../logger';
+import getDomain from '../functions/getDomain';
 
 class RegistrationDate extends Test {
   public name = 'RegistrationDate';
 
   public async test({ url }: TestParameters): Promise<Result> {
     logger.info(`Starting ${this.constructor.name} test...`);
 
-    const registrationDate = await this.getRegistrationDate((new URL(url).hostname));
+    const registrationDate = await this.getRegistrationDate(getDomain(url));
 
     const diffInMs = (new Date(registrationDate)).getTime() - (new Date()).getTime();
     const diffInDays = diffInMs / (1000 * 60 * 60 * 24);

src/functions/getDomain.ts

@@ -0,0 +1,16 @@
+const getDomain = (url: string): string => {
+  const hostname = (new URL(url)).hostname;
+  const parts = hostname.split('.');
+
+  if (parts.length === 2) {
+    return hostname;
+  }
+
+  if (parts.length === 3 && parts[1].length > parts[2].length) {
+    return hostname.replace(`${parts[0]}.`, '');
+  }
+
+  return hostname;
+}
+
+export default getDomain;