#orderos/app/controllers/concerns/user_session.rb
module OneTest
    module UserSession
        def self.included base
            base.class_eval do
                    helper_method :logged_in?
                    helper_method :current_user
            end
        end

        def signin_user user
            session[:user_id] = user.id
        end

        def logout_user
            session[:user_id] = nil
        end

        def logged_in? 
            !!session[:user_id]
        end

        def current_user
            if logged_in?
                @current_user ||= User.find(session[:user_id]) 
            else
                nil
            end
        end
    end
end

#orderos/app/controllers/application_controller.rb
class ApplicationController < ActionController::Base
    include OneTest::UserSession

end

错误

请问这是什么原因，名字也没错呀？