I'd rather use an interface to let people add behavior on existing Exception (like we do with
UnrecoverableExceptionInterface)

I dont follow you, I could create an interface, and implementing it, but what could you add to the Exception? I'll not used anyway

We already have a mechanism to stop the worker using eventDispatcher.

Yes I know, but this is more complex IMHO. Having something native is way more efficient
And BTW, 2 people already asked me how do to that :) And the issue receive a good feedback.

but what could you add to the Exception?

hmm.. nothing, It's just a Marker interface

interface StopWorkerExceptionInterface extends \Throwable
{
}
class StopWorkerException extends RuntimeException implements StopWorkerExceptionInterface
{
}

if ($throwable instanceof StopWorkerExceptionInterface) {
    $this->stop();
}

That would allow people use

class MyBusinessException implements StopWorkerExceptionInterface 
{
}

Instead of

try {
} catch (MyBusinessException $e) {
    throw new StopWorkerExceptionInterface(??, ??, $e);
}

I see how much this can be handy and simple, but throwing such an exception from e.g. a message handler feels weird to me. Stopping the worker is a consequence of an error, not an error on its own.
I agree that hooking into worker lifecycle events sounds better from a design pov.
Adding a sample listener to the docs like the one showed by @jderusse may be enough to fix this issue and could avoid having several paths for the same goal.

I agree this PR could leverage the Event Dispatcher System. But messenger could work without messenger, so the exception would become useless... But I think we don't care.

But IMHO this should not be a doc cookbook. The proposed system is really hackish. Many (good) developers did not find it by them-self.

Let's add a native / simple behavior here.

• I added an interface
• the system uses the Event Dispatch

I have rebased this PR and added some tests. There are 9 👍🏼 on the issue, so I do think we should consider to merge this PR

Thank you @lyrixx.