Add unit tests for helpers

**Feature request**
It would be great to have backup for validation.

**Use case**
Many users need this functionality for production deployments.

**Implementation idea**
Add a new config option `enable_backup` with default `false`.

No files, helper names, or test paths are identified. Start by locating the configuration entry point and existing helper tests, then clarify how validation should support backups and where enable_backup belongs; done means coverage for the helpers and a default value of false for the new option.

Written by the indexing model from the issue text.