test/sockjs.coffee tests server-side sockjs but there is no client-side testing as test/client.coffee only tests browserchannel. Also all comments in test/sockjs.coffee refer to browserchannel.
This is pending implementation of #122.
In the rewrite branch, I'm banishing all the transports to separate repositories. So I'm punting on this. The excellant SockJS support will need to be rewritten for the new world, and when it is we should add tests then.