Detect setting default value

[hansbogert]

Perhaps this is already possible, but I'd see value in detecting if a module instantiation is setting a module's input variables to their default value. If so, these input variables would not have to be set.

I'm assuming the module author adheres to strict semantic versioning and that changing default values would be breaking change which should be communicated.

[wata727]

It's an interesting idea, but unfortunately the current SDK API doesn't support this use case.

Finding the source of module calls and analyzing the module variable definitions is not impossible, but it is not easy. Probably worth considering when redesigning the interface in terraform-linters/tflint-plugin-sdk#193.