dns: Add dns/promises alias

doc/api/dns.md

@@ -611,7 +611,7 @@ earlier ones time out or result in some other error.
 
 The `dns.promises` API provides an alternative set of asynchronous DNS methods
 that return `Promise` objects rather than using callbacks. The API is accessible
-via `require('dns').promises`.
+via `require('dns').promises` or `require('dns/promises')`.
 
 ### Class: `dnsPromises.Resolver`
 <!-- YAML

lib/dns/promises.js

@@ -0,0 +1,3 @@
+'use strict';
+
+module.exports = require('internal/dns/promises');

node.gyp

@@ -48,6 +48,7 @@
       'lib/cluster.js',
       'lib/dgram.js',
       'lib/dns.js',
+      'lib/dns/promises.js',
       'lib/domain.js',
       'lib/events.js',
       'lib/fs.js',

test/es-module/test-esm-dns-promises.mjs

@@ -0,0 +1,14 @@
+// Flags: --expose-internals
+import '../common/index.mjs';
+import assert from 'assert';
+import { lookupService } from 'dns/promises';
+
+const invalidAddress = 'fasdfdsaf';
+
+assert.throws(() => {
+  lookupService(invalidAddress, 0);
+}, {
+  code: 'ERR_INVALID_OPT_VALUE',
+  name: 'TypeError',
+  message: `The value "${invalidAddress}" is invalid for option "address"`
+});

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

@@ -0,0 +1,6 @@
+'use strict';
+
+require('../common');
+const assert = require('assert');
+
+assert.strictEqual(require('dns/promises'), require('dns').promises);