Question about behavior of unsubscribe()

[ottomata]

I see that Consumer::Unsubscribe returns RdKafka::ERR__STATE if it is called on a not-yet-subscribed consumer. However, there doesn't seem to be a way to infer subscription state via the node client. Should I manage this state myself, or can we add a consumer.subscriptions() method to get the current subscriptions? And/or, perhaps Consumer::Unsubscribe should just be a no-op if the consumer has no current subscriptions.

While looking into this, I noticed that consumer.subscribe() takes a cb, but as far as I can tell it is not invoked. Should it be?

[webmakersteve]

Originally, unsubscribe was idempotent and you could call it as many times as you want because it didn't matter if you actually were subscribed, but I changed that behavior because I thought it encouraged not caring about the state. I think the C++ should still throw but that this behavior should be encapsulated in the JS part of the library.

About the callback: I think that's a remnant from an old version where subscribe was async. I found that there wasn't really much of a reason for it so I changed it to sync. I'll make sure to update the docs and remove the parameter.

[webmakersteve]

Unsubscribe will no longer throw when you are not currently subscribed. I believe this satisfies the issue!