Conditional inheritance: base class depend on environment variable

Question

I have two abstracts classes, 'ValidationsWithStorage' inherits 'Validations'

   public abstract class Validations {
    // methods..
   }

   public abstract class ValidationsWithStorage : Validations { 
    // ... 
    }

I also have a class:

public abstract class TestsValidations : T

T should be depend on the environment variable:

Environment.GetEnvironmentVariable("useStorage") 

If this variable is null I want that T will be Validations. Else, I want that T will be ValidationsWithStorage.

What is the best way to do it?

Thanks

Answer 1

You can do that using conditional compilation:

public abstract class TestsValidations
#if USESTORAGE
    : ValidationsWithStorage
#else
    : Validations
#endif
{

}

You can set it in project configuration or by passing additional parameters to msbuild: /p:DefineConstants="USESTORAGE"

I don't think this is good design, but it is doable.