Add session helpers

app/helpers/application_helper.rb

@@ -1,2 +1,11 @@
+# frozen_string_literal: true
+
 module ApplicationHelper
+  def logged_in?
+    session[:user_id].present?
+  end
+
+  def current_user
+    @current_user ||= User.find(session[:user_id]) if logged_in?
+  end
 end