render nothing: true has been removed from Rails

Use head instead

app/controllers/ping_controller.rb

@@ -2,9 +2,9 @@ class PingController < ApplicationController
   def index
     Rails.logger.silence do
       if (ActiveRecord::Base.connected?)
-        render nothing: true, status: 200, content_type: "application/json"
+        head :ok
       else
-        render nothing: true, status: 500, content_type: "application/json"
+        head :internal_server_error
       end
     end
   end

spec/controllers/new_gestionnaire/dossiers_controller_spec.rb

@@ -21,7 +21,7 @@ describe NewGestionnaire::DossiersController, type: :controller do
 
         expect(controller).to receive(:send_data)
           .with('pdf content', filename: 'attestation.pdf', type: 'application/pdf') do
-            controller.render nothing: true
+            controller.head :ok
           end
 
         get :attestation, params: { procedure_id: procedure.id, dossier_id: dossier.id }

spec/controllers/new_user/dossiers_controller_spec.rb

@@ -56,7 +56,7 @@ describe NewUser::DossiersController, type: :controller do
 
         expect(controller).to receive(:send_data)
           .with('pdf content', filename: 'attestation.pdf', type: 'application/pdf') do
-            controller.render nothing: true
+            controller.head :ok
           end
 
         get :attestation, params: { dossier_id: dossier.id }