manages permissions for debate editing

app/controllers/debates_controller.rb

@@ -1,7 +1,8 @@
 class DebatesController < ApplicationController
   before_action :set_debate, only: [:show, :edit, :update]
-  before_action :authenticate_user!, only: [:new, :create]
-  
+  before_action :authenticate_user!, except: [:show, :index]
+  before_action :validate_ownership, only: [:edit, :update]
+
   def index
     if params[:tag]
       @debates = Debate.tagged_with(params[:tag])
@@ -42,4 +43,8 @@ class DebatesController < ApplicationController
       params.require(:debate).permit(:title, :description, :tag_list, :terms_of_service)
     end
 
+    def validate_ownership
+      raise ActiveRecord::RecordNotFound unless @debate.editable_by?(current_user)
+    end
+
 end