test: add test-dns-promises-lookupService

test/parallel/test-dns-promises-lookupService.js

@@ -0,0 +1,19 @@
+'use strict';
+
+const common = require('../common');
+
+const assert = require('assert');
+const dnsPromises = require('dns').promises;
+
+dnsPromises.lookupService('127.0.0.1', 22).then(common.mustCall((result) => {
+  assert.strictEqual(result.service, 'ssh');
+  assert.strictEqual(typeof result.hostname, 'string');
+  assert.notStrictEqual(result.hostname.length, 0);
+}));
+
+// Use an IP from the RFC 5737 test range to cause an error.
+// Refs: https://tools.ietf.org/html/rfc5737
+assert.rejects(
+  () => dnsPromises.lookupService('192.0.2.1', 22),
+  { code: /^(?:ENOTFOUND|EAI_AGAIN)$/ }
+);