count-anything/app/channels/application_cable/connection.rb

module ApplicationCable
  class Connection < ActionCable::Connection::Base
    identified_by :current_user

    def connect
      self.current_user = find_verified_user
    end

    private
    def find_verified_user
      if (verified_user = env['warden'].user)
        verified_user
      else
        nil
      end
    end
  end
end