describe Topic do
   describe"scopes" do

     before do
       @public_topic = Topic.create # default is public
       @private_topic = Topic.create(public: false)
     end

     describe"publicly_viewable" do
       it"returns a relation of all public topics" do
         expect(Topic.publicly_viewable).to eq( [@public_topic] )
       end
     end

     describe"privately_viewable" do
       it"returns a relation of all private topics" do
         expect(Topic.privately_viewable).to eq( [@private_topic] )
       end
     end

     describe"visible_to(user)" do
       it"returns all topics if the user is present" do
         user = User.new
         expect(Topic.visible_to(user)).to eq(Topic.all)
       end

       it"returns only public topics if user is nil" do
         expect(Topic.visible_to(nil)).to eq(Topic.publicly_viewable)
       end
     end
  end
end