tasks: don't abort rollback when a dossier fails

Instead print a warning, and continue rolling back the other dossiers.

app/services/piece_justificative_to_champ_piece_jointe_migration_service.rb

@@ -139,7 +139,14 @@ class PieceJustificativeToChampPieceJointeMigrationService
   def rollback_migration!(types_de_champ_pj)
     types_de_champ_pj.each do |type_champ|
       # First destroy all the individual champs on dossiers
-      type_champ.champ.each { |c| destroy_champ_pj(c.dossier.reload, c) }
+      type_champ.champ.each do |champ|
+        begin
+          destroy_champ_pj(champ.dossier.reload, champ)
+        rescue => e
+          rake_puts e
+          rake_puts "Rolling back of champ #{champ.id} failed. Continuing to roll back…"
+        end
+      end
       # Now we can destroy the type de champ itself,
       # without cascading the timestamp update on all attached dossiers.
       type_champ.reload.destroy

spec/services/piece_justificative_to_champ_piece_jointe_migration_service_spec.rb

@@ -276,5 +276,26 @@ describe PieceJustificativeToChampPieceJointeMigrationService do
         expect { try_convert(procedure) }.not_to change { dossier.champs.count }
       end
     end
+
+    context 'when rolling back a dossier fails' do
+      before do
+        allow(service).to receive(:destroy_champ_pj)
+          .with(having_attributes(id: dossier.id), anything)
+          .and_raise(StandardError)
+        allow(service).to receive(:destroy_champ_pj)
+          .with(any_args)
+          .and_call_original
+      end
+
+      it 'continues to roll back the other dossiers' do
+        expect { try_convert(procedure) }
+          .not_to change { failing_dossier.champs.count }
+      end
+
+      it 'does not creates types de champ on the procedure' do
+        expect { try_convert(procedure) }
+          .not_to change { procedure.types_de_champ.count }
+      end
+    end
   end
 end