params is now an object and no longer a hash

spec/controllers/new_user/dossiers_controller_spec.rb

@@ -18,7 +18,7 @@ describe NewUser::DossiersController, type: :controller do
     let(:user) { create(:user) }
 
     before do
-      @controller.params[:dossier_id] = asked_dossier.id
+      @controller.params = @controller.params.merge(dossier_id: asked_dossier.id)
       expect(@controller).to receive(:current_user).and_return(user)
       allow(@controller).to receive(:redirect_to)