code: function runServer(cb) {
    function onStdOut(data) {
      const time = new Date().toTimeString();
      const match = data.toString('utf8').match(RUNNING_REGEXP);
  
      process.stdout.write(time.replace(/.*(\d{2}:\d{2}:\d{2}).*/, '[$1] '));
      process.stdout.write(data);
  
      if (match) {
        server.stdout.removeListener('data', onStdOut);
        server.stdout.on('data', x => process.stdout.write(x));
        if (cb) {
          cb(null, match[1]);
        }
      }
    }
  
    if (server) {
      server.kill('SIGTERM');
    }
  
    server = cp.spawn('node', [serverPath], {
      env: Object.assign({ NODE_ENV: 'development' }, process.env),
      silent: false,
    });
  
    server.stdout.on('data', onStdOut);
    server.stderr.on('data', x => process.stderr.write(x));
  }
docs: Launch or restart the Node.js server