AVD::Spec::ConstraintValidatorTestCase leverages the AVD::Spec::MockValidator type. Because of this, if a constraint uses the validator off the context it wouldn't actually run those violations causing the specs to not pass since it thinks there are no violations. An example of this is the ISIN constraint.

This constraint should be updated to remove the validator ivar with something like self.context.validator.validate(number, AVD::Constraints::Luhn.new).empty?. But we'll also need to handle this somehow in the specs. TBD on how to do that given we can't just mock the values it returns.