add tests

onadata/apps/api/tests/viewsets/test_data_viewset.py

@@ -1791,6 +1791,10 @@ def test_deletion_of_bulk_submissions(self, mock_cache_set):
         response = view(request, pk=formid)
 
         self.assertEqual(response.status_code, 200)
+        self.assertEqual(
+            response.data.get("message"),
+            "%d records were deleted" % len(records_to_be_deleted),
+        )
         self.xform.refresh_from_db()
         current_count = self.xform.instances.filter(deleted_at=None).count()
         self.assertNotEqual(current_count, initial_count)
@@ -2023,6 +2027,10 @@ def test_delete_submissions(self):
         response = view(request, pk=formid)
 
         self.assertEqual(response.status_code, 200)
+        self.assertEqual(
+            response.data.get("message"),
+            "%d records were deleted" % len(deleted_instances_subset),
+        )
 
         # Test that num of submissions for the form is successfully updated
         self.xform.refresh_from_db()
@@ -2037,6 +2045,7 @@ def test_delete_submissions(self):
         response = view(request, pk=formid)
 
         self.assertEqual(response.status_code, 200)
+        self.assertEqual(response.data.get("message"), "3 records were deleted")
 
         # Test project details updated successfully
         self.assertEqual(

onadata/apps/api/viewsets/data_viewset.py

@@ -384,6 +384,7 @@ def destroy(self, request, *args, **kwargs):
             else:
                 instance_ids = None
 
+            initial_num_of_submissions = self.object.num_of_submissions
             delete_xform_submissions_async.delay(
                 self.object.id,
                 instance_ids,
@@ -395,9 +396,12 @@ def destroy(self, request, *args, **kwargs):
                 instance_ids,
                 XFORM_SUBMISSIONS_DELETING_TTL,
             )
+            number_of_records_deleted = (
+                len(instance_ids) if instance_ids else initial_num_of_submissions
+            )
 
             return Response(
-                data={"message": f"{len(instance_ids)} records were deleted"},
+                data={"message": f"{number_of_records_deleted} records were deleted"},
                 status=status.HTTP_200_OK,
             )