Prefer to use overrides on PipelinesController

app/controllers/projects/pipelines_controller.rb

@@ -69,7 +69,7 @@ class Projects::PipelinesController < Projects::ApplicationController
 
         render json: PipelineSerializer
           .new(project: @project, current_user: @current_user)
-          .represent(@pipeline, grouped: true)
+          .represent(@pipeline, show_represent_params)
       end
     end
   end
@@ -157,6 +157,10 @@ class Projects::PipelinesController < Projects::ApplicationController
     end
   end
 
+  def show_represent_params
+    { grouped: true }
+  end
+
   def create_params
     params.require(:pipeline).permit(:ref, variables_attributes: %i[key secret_value])
   end