server.js

const http = require('http');
const app = require('./app');

const server = http.createServer(app);
const port = 3000;
server.listen(port);
/**
 * Event listener for HTTP server "error" event.
 */

const onError = (error) => {
  if (error.syscall !== 'listen') {
    throw error;
  }

  const bind = typeof port === 'string'
    ? `Pipe ${port}`
    : `Port ${port}`;

  // handle specific listen errors with friendly messages
  switch (error.code) {
    case 'EACCES':
      console.error(`${bind} requires elevated privileges`);
      process.exit(1);
      break;
    case 'EADDRINUSE':
      console.error(`${bind} is already in use`);
      process.exit(1);
      break;
    default:
      throw error;
  }
};

/**
 * Event listener for HTTP server "listening" event.
 */

const onListening = () => {
  const addr = server.address();
  const bind = typeof addr === 'string'
    ? `pipe ${addr}`
    : `port ${addr.port}`;
  console.info('\n\n*********** STARTING service **************');
  console.info(`Web server listening at: ${bind}`);
};
server.on('error', onError);
server.on('listening', onListening);