dns: add dns/promises alias

PR-URL: #32953 Reviewed-By: Anna Henningsen <[email protected]> Reviewed-By: Colin Ihrig <[email protected]> Reviewed-By: Ruben Bridgewater <[email protected]>

Author: shisama

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 +1,5 @@
+'use strict';
+
+constdnsPromises=require('internal/dns/promises');
+dnsPromises.setServers=require('dns').setServers;
+module.exports=dnsPromises;

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';
+importassertfrom'assert';
+import{lookupService}from'dns/promises';
+
+constinvalidAddress='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');
+constassert=require('assert');
+
+assert.strictEqual(require('dns/promises'),require('dns').promises);

test/parallel/test-dns-setservers-type-check.js

@@ -85,3 +85,36 @@ const promiseResolver = new dns.promises.Resolver();
 );
 });
 }
+
+// This test for 'dns/promises'
+{
+const{
+ setServers
+}=require('dns/promises');
+
+// This should not throw any error.
+(async()=>{
+setServers(['127.0.0.1']);
+})();
+
+[
+[null],
+[undefined],
+[Number(addresses.DNS4_SERVER)],
+[
+{
+address: addresses.DNS4_SERVER
+}
+]
+].forEach((val)=>{
+consterrObj={
+code: 'ERR_INVALID_ARG_TYPE',
+name: 'TypeError',
+message: 'The "servers[0]" argument must be of type string.'+
+common.invalidArgTypeHelper(val[0])
+};
+assert.throws(()=>{
+setServers(val);
+},errObj);
+});
+}