fix(export): no crash on empty repetitions

app/models/dossier.rb

@@ -482,7 +482,7 @@ class Dossier < ApplicationRecord
         end
 
       dossiers.each do |dossier|
-        load_dossier(dossier, champs_by_dossier[dossier.id], champs_by_dossier_by_parent[dossier.id])
+        load_dossier(dossier, champs_by_dossier[dossier.id], champs_by_dossier_by_parent[dossier.id] || {})
       end
     end
 

app/services/procedure_export_service.rb

@@ -102,11 +102,12 @@ class ProcedureExportService
       .repetition
       .filter_map do |type_de_champ_repetition|
         types_de_champ = procedure.types_de_champ_for_procedure_presentation(type_de_champ_repetition).to_a
+        rows = champs_by_stable_id.fetch(type_de_champ_repetition.stable_id, []).flat_map(&:rows_for_export)
 
-        if types_de_champ.present?
+        if types_de_champ.present? && rows.present?
           {
             sheet_name: type_de_champ_repetition.libelle_for_export,
-            instances: champs_by_stable_id.fetch(type_de_champ_repetition.stable_id, []).flat_map(&:rows_for_export),
+            instances: rows,
             spreadsheet_columns: Proc.new { |instance| instance.spreadsheet_columns(types_de_champ) }
           }
         end

spec/services/procedure_export_service_spec.rb

@@ -405,6 +405,18 @@ describe ProcedureExportService do
           expect(subject.sheets.map(&:name)).to eq(['Dossiers', 'Etablissements', 'Avis', another_champ_repetition.libelle_for_export, champ_repetition.libelle_for_export])
         end
       end
+
+      context 'with empty repetition' do
+        before do
+          dossiers.flat_map { |dossier| dossier.champs.filter(&:repetition?) }.each do |champ|
+            champ.champs.destroy_all
+          end
+        end
+
+        it 'should not have data' do
+          expect(repetition_sheet).to be_nil
+        end
+      end
     end
   end