dns: remove redundant code using common variable

`validFamilies` variable is defined 2 times, so remove redundant code by defining `validFamilies` in util. Plus, apply the same approach to `validDnsOrders` because it's also used multiple times. PR-URL: #57386 Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Daeyeon Jeong <daeyeon.dev@gmail.com> Reviewed-By: Zijian Liu <lxxyxzj@gmail.com>

Author: deokjinkim

lib/dns.js

@@ -46,6 +46,8 @@ const {
  getDefaultResultOrder,
  setDefaultResultOrder,
  errorCodes: dnsErrorCodes,
+ validDnsOrders,
+ validFamilies,
 } = require('internal/dns/utils');
 const {
  Resolver,
@@ -138,7 +140,6 @@ function onlookupall(err, addresses) {
 
 // Easy DNS A/AAAA look up
 // lookup(hostname, [options,] callback)
-const validFamilies = [0, 4, 6];
 function lookup(hostname, options, callback) {
  let hints = 0;
  let family = 0;
@@ -192,7 +193,7 @@ function lookup(hostname, options, callback) {
  dnsOrder = options.verbatim ? 'verbatim' : 'ipv4first';
  }
  if (options?.order != null) {
- validateOneOf(options.order, 'options.order', ['ipv4first', 'ipv6first', 'verbatim']);
+ validateOneOf(options.order, 'options.order', validDnsOrders);
  dnsOrder = options.order;
  }
  }

lib/internal/dns/promises.js

@@ -16,6 +16,8 @@ const {
  getDefaultResultOrder,
  setDefaultResultOrder,
  setDefaultResolver,
+ validDnsOrders,
+ validFamilies,
 } = require('internal/dns/utils');
 
 const {
@@ -177,7 +179,6 @@ function createLookupPromise(family, hostname, all, hints, dnsOrder) {
  });
 }
 
-const validFamilies = [0, 4, 6];
 /**
  * Get the IP address for a given hostname.
  * @param {string} hostname - The hostname to resolve (ex. 'nodejs.org').
@@ -225,7 +226,7 @@ function lookup(hostname, options) {
  dnsOrder = options.verbatim ? 'verbatim' : 'ipv4first';
  }
  if (options?.order != null) {
- validateOneOf(options.order, 'options.order', ['ipv4first', 'ipv6first', 'verbatim']);
+ validateOneOf(options.order, 'options.order', validDnsOrders);
  dnsOrder = options.order;
  }
  }

lib/internal/dns/utils.js

@@ -200,14 +200,16 @@ class ResolverBase {
 
 let defaultResolver;
 let dnsOrder;
+const validDnsOrders = ['verbatim', 'ipv4first', 'ipv6first'];
+const validFamilies = [0, 4, 6];
 
 function initializeDns() {
  const orderFromCLI = getOptionValue('--dns-result-order');
  if (!orderFromCLI) {
  dnsOrder ??= 'verbatim';
  } else {
  // Allow the deserialized application to override order from CLI.
- validateOneOf(orderFromCLI, '--dns-result-order', ['verbatim', 'ipv4first', 'ipv6first']);
+ validateOneOf(orderFromCLI, '--dns-result-order', validDnsOrders);
  dnsOrder = orderFromCLI;
  }
 
@@ -279,7 +281,7 @@ function emitInvalidHostnameWarning(hostname) {
 }
 
 function setDefaultResultOrder(value) {
- validateOneOf(value, 'dnsOrder', ['verbatim', 'ipv4first', 'ipv6first']);
+ validateOneOf(value, 'dnsOrder', validDnsOrders);
  dnsOrder = value;
 }
 
@@ -353,4 +355,6 @@ module.exports = {
  errorCodes,
  createResolverClass,
  initializeDns,
+ validDnsOrders,
+ validFamilies,
 };