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

'use strict';
require('../common');
const { addresses } = require('../common/internet');
const assert = require('assert');
const dns = require('dns');
const resolver = new dns.promises.Resolver();
const dnsPromises = dns.promises;
const promiseResolver = new dns.promises.Resolver();

{
  [
    null,
    undefined,
    Number(addresses.DNS4_SERVER),
    addresses.DNS4_SERVER,
    {
      address: addresses.DNS4_SERVER
    }
  ].forEach((val) => {
    const errObj = {
      code: 'ERR_INVALID_ARG_TYPE',
      name: 'TypeError',
      message: 'The "servers" argument must be of type Array. Received type ' +
      typeof val
    };
    assert.throws(
      () => {
        dns.setServers(val);
      }, errObj
    );
    assert.throws(
      () => {
        resolver.setServers(val);
      }, errObj
    );
    assert.throws(
      () => {
        dnsPromises.setServers(val);
      }, errObj
    );
    assert.throws(
      () => {
        promiseResolver.setServers(val);
      }, errObj
    );
  });
}

{
  [
    [null],
    [undefined],
    [Number(addresses.DNS4_SERVER)],
    [
      {
        address: addresses.DNS4_SERVER
      }
    ]
  ].forEach((val) => {
    const errObj = {
      code: 'ERR_INVALID_ARG_TYPE',
      name: 'TypeError',
      message: 'The "servers[0]" argument must be of type string. ' +
               `Received type ${typeof val[0]}`
    };
    assert.throws(
      () => {
        dns.setServers(val);
      }, errObj
    );
    assert.throws(
      () => {
        resolver.setServers(val);
      }, errObj
    );
    assert.throws(
      () => {
        dnsPromises.setServers(val);
      }, errObj
    );
    assert.throws(
      () => {
        promiseResolver.setServers(val);
      }, errObj
    );
  });
}