Checking for existing variables?

[rui1610]

I've just started using terraform_compliance today and was wondering, whether I could use it to check for the definition of variables.
In essence I'd like to check whether specific variables have been defined to ensure compliance across multiple terraform scripts. E.g. a variable "foo" and "moo" needs to be in the variables.tf file.
Is that possible? I've already tried a couple of times, but always getting the message, that the features and scenarios passed.
This is what I've already tried

Feature: Certain variables should always be defined

  Scenario Outline: Naming Standard on all available variables
    Given I have not defined variable foo or moo
    Then scenario should fail

Thanks so much for your help!