'use strict';

const common = require('../common');

var mustCall = common.mustCall;

const assert = require('assert');

const dgram = require('dgram');

const dns = require('dns');

var socket = dgram.createSocket('udp4');

var buffer = Buffer.from('gary busey');

dns.setServers([]);

socket.once('error', onEvent);

// assert that:

// * callbacks act as "error" listeners if given.

// * error is never emitter for missing dns entries

// if a callback that handles error is present

// * error is emitted if a callback with no argument is passed

socket.send(buffer, 0, buffer.length, 100,

'dne.example.com', mustCall(callbackOnly));

function callbackOnly(err) {

assert.ok(err);

socket.removeListener('error', onEvent);

socket.on('error', mustCall(onError));

socket.send(buffer, 0, buffer.length, 100, 'dne.example.com');

}

function onEvent(err) {

common.fail('Error should not be emitted if there is callback');

}

function onError(err) {

assert.ok(err);

socket.close();

}