promise.js

this.addNewListener = function(user) {

  joinChannel(user.name);
  return addNewChannelCache(user)
    .then(function(data) {
      return cache.getAsync(user.name);
    })
    .then(function(obj) {
      if (obj == null) {
        throw new Exception('Object was not in cache');
      } else {
        io.of('/' + user._id);
        return obj;
      }
    });
}