I don't know about Cobra, but I would say Nim has first class support for unit tests. If you check out the "Testable documentaion examples" section of the artic

I don't know about Cobra, but I would say Nim has first class support for unit tests. If you check out the "Testable documentaion examples" section of the article, it shows they've even added support for testing sample code in inline function documentation. This is a really interesting approach. I don't use Nim myself (not a "systems" programmer - what a silly term that is, we all make "systems" but I guess that boat has sailed) but I'm interested in applying a similar approach in other languages.