node/test/sequential/test-net-connect-local-error.js

'use strict';
const common = require('../common');
const assert = require('assert');
const net = require('net');

const client = net.connect({
  port: common.PORT + 1,
  localPort: common.PORT,
  localAddress: common.localhostIPv4
});

client.on('error', common.mustCall(function onError(err) {
  assert.strictEqual(err.syscall, 'connect');
  assert.strictEqual(err.code, 'ECONNREFUSED');
  assert.strictEqual(
    err.localPort,
    common.PORT,
    `${err.localPort} !== ${common.PORT} in ${err}`
  );
  assert.strictEqual(
    err.localAddress,
    common.localhostIPv4,
    `${err.localAddress} !== ${common.localhostIPv4} in ${err}`
  );
  assert.strictEqual(
    err.message,
    `connect ECONNREFUSED ${err.address}:${err.port} ` +
    `- Local (${err.localAddress}:${err.localPort})`
  );
}));