People say you can't get unit test support from Visual Studio for native code. That's not strictly true. Your tests will need to be managed code, but that doesn't mean the code you're testing needs to be.
As I hope you know, it's super easy to call native C++ code from C++/CLI - include the header, link to the lib. So here's the deal. Make yourself a lib that holds all the code you want to test. This can be completely native code, no problem. Build your UI (or your web services layer or your service or server or whatnot, I don't mean by UI an actual interface that a user clicks and types to, I just mean the part of your app that consumes your business logic) in native code if you like. Or in managed code, that's cool too. Then create a C++/CLI test project that includes the header for the logic, and links to the lib. There you go.
For the gory details including precisely what menu items to select and how to set up the project, John Socha-Leialoha
has you covered. I love his conclusion:
After so many years writing in C#, I never thought I would enjoy C++
programming again. I was wrong. Using TDD to write C++ code is almost as nice as
writing C# code, and I’m really enjoying the experience.