'use strict'; const dgram = require('dgram'); const options = { type: 'udp4', reusePort: true }; function checkSupportReusePort() { return new Promise((resolve, reject) => { const socket = dgram.createSocket(options); socket.bind(0); socket.on('listening', () => { socket.close(resolve); }); socket.on('error', (err) => { console.log('The `reusePort` option is not supported:', err.message); socket.close(); reject(err); }); }); } module.exports = { checkSupportReusePort, options, };