When errors are not handled, the Node applications crash. To catch unexpected errors, we have two options: to use process.on('uncaughtException', ..) or the native domains API (which might be removed in a future version of Node).

If we decide to catch these unexpected exceptions, it is extremely important to not ignore the error and just move on. Whatever we do with the error, we still need to exit the process because it's in an inconsistent or unrecoverable state.

Here's a small snippet of how we can handle uncaught exceptions:

process.on('uncaughtException', function (err) {
  console.error((new Date).toUTCString() + ' uncaughtException:', err.message);
  console.error(err.stack);
  process.exit(1);
});

throw new Error('bad things happen');