Okay. I messed up. There is only a problem if there is two separate muxed connection to the same node (for instance two tcp connections with spdy). And that will only happen under the very specific test conditions I had.
Sorry about that.
The good news is that no patch is needed :)

Parallel dials will cause this as well, for example these new tests on switch: https://github.com/libp2p/js-libp2p-switch/pull/298/files#diff-063533a50438d54e519fdd9f9161bc82.

I think my main concern here is that the peer will always be in the peerBook, so we'll never fire the the disconnect event. I think we may need to actually check for connections with the PeerId via https://github.com/libp2p/js-libp2p-switch/blob/v0.41.4/src/connection/manager.js#L62.

The more i look at the connections management the more confused i get :)

From what i can see, the connections object (https://github.com/libp2p/js-libp2p-switch/blob/v0.41.4/src/connection/manager.js#L22) only contains the real connection that are being used for multiplexing.
So if libp2p is running without muxing, the connections object is always empty and hangup does not work (https://github.com/nikor/js-libp2p-test/blob/master/test1.js). Is that expected behavior?

It also seems like the connection is not removed from the object if the other end closes it (https://github.com/nikor/js-libp2p-test/blob/master/test2.js). But i think that is a seperate issue.

But about the current problem. I can only get libp2p to emit 'peer:disconnect' if i do a hangup, but that is expected behavior. How do i close only inbound or outbound connections?

The more i look at the connections management the more confused i get :)

Yeah, the connection logic is pretty confusing. It's getting better, but still has a ways to go.

So if libp2p is running without muxing, the connections object is always empty and hangup does not work (https://github.com/nikor/js-libp2p-test/blob/master/test1.js). Is that expected behavior?

No, hangup should work, it's just not in there yet as the focus has been primarily on muxed connections because they're a more efficient use of connections. We do need to do this though, to avoid leaking connections.

But about the current problem. I can only get libp2p to emit 'peer:disconnect' if i do a hangup, but that is expected behavior. How do i close only inbound or outbound connections?

That is being done here, libp2p/js-libp2p-switch#298. The work is done, but there is a bug in the libp2p tests I haven't been able to look at yet.

The connection manager in the switch now keeps track of the connections and will only emit when all connections to that peer have been removed, https://github.com/libp2p/js-libp2p-switch/blob/v0.42.11/src/connection/manager.js#L86.