✅ Add tests for DNS service

src/modules/dns/dns.service.spec.ts

@@ -0,0 +1,22 @@
+import { MxRecord } from 'dns';
+import { DnsService } from './dns.service';
+
+const dnsService = new DnsService();
+
+describe('DnsService', () => {
+  describe('lookup', () => {
+    it('gets MX records', async () => {
+      const result = await dnsService.lookup('google.com', 'MX');
+      expect(result).toBeDefined();
+    });
+    it('gets correct MX record', async () => {
+      const result = (await dnsService.lookup(
+        'google.com',
+        'MX',
+      )) as MxRecord[];
+      expect(
+        result.find((i) => i.exchange === 'aspmx.l.google.com'),
+      ).toBeTruthy();
+    });
+  });
+});