ruud/src/exit.js

the player who serves

const signals = [
  'SIGTERM',
  'SIGINT',
  'EADDRINUSE',
  'unhandledRejection',
  'uncaughtException'
];

export default log => {
  const exitQueue = [];

  const stop = async () => {
    while (exitQueue.length) {
      const [name, func] = exitQueue.shift();
      await func();
      log(`<magenta>${name} shut down</magenta>`);
    }
  };

  const handle = async (signal, message) => {
    if (/^SIG/.test(signal)) process.stdout.write('\b\b\n'); // remove ^C

    log(`<red>${signal}</red>`, message);

    if (/^(SIG)/.test(signal) || /EADDR/.test(message + signal)) {
      await stop();

      // assume --watch and make time for stdout consumption
      if (signal === 'SIGTERM') {
        process.stdout.write('\n');
        await new Promise(r => setTimeout(r, 2000));
      }

      process.exit(0);
    }
  };

  signals.forEach(signal => process.on(signal, handle));

  return {
    add(name, func) {
      exitQueue.push([name, func]);
    },
    stop
  };
}