QueueEvents class never exits

[seawatts]

Whenever I try to use the QueueEvents class my process hangs forever because of this line: https://github.com/taskforcesh/bullmq/blob/master/src/classes/queue-events.ts#L65
However, If i just remove the QueueEvents class then it will exit correctly.

Example:

// test.ts

import { Worker, Queue, QueueEvents } from 'bullmq';

(async () => {

const queueName = `test-queue-1`;
const queue = new Queue(queueName);

const queueEvents = new QueueEvents(queueName)
await queueEvents.waitUntilReady();

const worker = new Worker(queueName, () => console.log('processed'));

await queue.add('hi', {});

await new Promise(resolve => queueEvents.on('completed', resolve));

await worker.close();
await queue.close();
await queueEvents.close();
})();

I used wtfnode in order to test this and got these results

$ tsc
$ wtfnode dist/test.js

completed

[WTF Node?] open handles:
- File descriptors: (note: stdio always exists)
  - fd 1 (tty) (stdio)
  - fd 2 (tty) (stdio)
- Sockets:
  - 127.0.0.1:50644 -> 127.0.0.1:6379
- Timers:
  - (5000 ~ 5 s) (anonymous) @ ./node_modules/bullmq/dist/utils.js:33

It looks like the error here https://github.com/taskforcesh/bullmq/blob/master/src/classes/queue-events.ts#L62 is Connection is closed.

[manast]

I do not understand, the line you are referring to is a 5 seconds delay, so how is it hanging it forever?

[seawatts]

I agree, I'm not sure. That's why I'm confused.

[seawatts]

Hmm, it looks like if I take QueueEvents out then it works fine. Maybe it's not closing the connection correctly?

[onehorsetown]

I suspect I see the problem here. worker.close() does not actually return a promise or await anything.

await worker.close();

Looking at

bullmq/src/classes/worker.ts

Line 370 in fccacee

this.closing = new Promise(async (resolve, reject) => {

you can see that Worker.close constructs a promise, but it does not return or await that promise. Basically it is creating a hanging promise that causes problems when you want to exit the process cleanly.

[manast]

@onehorsetown close should wait for closing. But the promise it is not "hanging", it has a very important function.

[manast]

#153

[manast]

AFAIK this is resolved now.