fix(champs): attach piece justificative

app/controllers/champs/piece_justificative_controller.rb

@@ -2,14 +2,24 @@ class Champs::PieceJustificativeController < ApplicationController
   before_action :authenticate_logged_user!
 
   def update
-    @champ = policy_scope(Champ).find(params[:champ_id])
+    if attach_piece_justificative_or_retry
-
-    @champ.piece_justificative_file.attach(params[:blob_signed_id])
-    if @champ.save
       render :show
     else
-      errors = @champ.errors.full_messages
+      render json: { errors: @champ.errors.full_messages }, status: 422
-      render :json => { errors: errors }, :status => 422
     end
   end
+
+  private
+
+  def attach_piece_justificative
+    @champ = policy_scope(Champ).find(params[:champ_id])
+    @champ.piece_justificative_file.attach(params[:blob_signed_id])
+    @champ.save
+  end
+
+  def attach_piece_justificative_or_retry
+    attach_piece_justificative
+  rescue ActiveRecord::StaleObjectError
+    attach_piece_justificative
+  end
 end