I tried with my Node.js module and it works… https://www.npmjs.org/package/node-twitch-irc
Source code: https://github.com/Schmoopiie/node-twitch-irc
Example of how to join a group channel with this module: https://github.com/Schmoopiie/node-twitch-irc/blob/master/examples/groups.js
Thanks,
Schmoopiie!