fix worker will die if the master exit

[harlentan]

No description provided.

[lamweili]

Similar to #1089, it's due to the way EventEmitter works.

If there is no listener to the 'error' event, the EventEmitter additionally throws the error, which in turn becomes uncaughtException that terminates the Node.js process. This portion has been overlooked and this PR patches it.

Events

Error events

When an error occurs within an EventEmitter instance, the typical action is for an 'error' event to be emitted. These are treated as special cases within Node.js.

If an EventEmitter does not have at least one listener registered for the 'error' event, and an 'error' event is emitted, the error is thrown, a stack trace is printed, and the Node.js process exits.

const myEmitter = new MyEmitter();
myEmitter.emit('error', new Error('whoops!'));
// Throws and crashes Node.js

To guard against crashing the Node.js process the domain module can be used. (Note, however, that the domain module is deprecated.)

As a best practice, listeners should always be added for the 'error' events.

const myEmitter = new MyEmitter();
myEmitter.on('error', (err) => {
  console.error('whoops! there was an error');
});
myEmitter.emit('error', new Error('whoops!'));
// Prints: whoops! there was an error

(src: https://nodejs.org/docs/latest/api/events.html#error-events)

[lamweili]

Might want to follow #1089 and flush the buffer on 'error' before it calls 'close'.