C++ & proper TDD

Question

Hi! I recently tried developing a small-sized project in C# and during the whole project our team used the Test-Driven-Development (TDD) technique (xunit, moq).

I really think this was awesome, because (when paired with C#) this approach allowed to relax when coding, relax when projecting and relax when refactoring. I suspect that all this TDD-stuff actually simplifies the coding process and, well, it allowed (eventually, for me) to get the same result with fewer brain cells working.

Right after that I tried using TDD paired with C++ (I used Google Test and Google Mock libraries), and, I don't know why but I actually think that TDD here was a step back in terms of rapid application development.

I had some moments when I had to spend huge amounts of time thinking of my tests, building proper mocks, rebuilding them and swearing at my monitor.

And, well, I obviously can't ask something like "what I did wrong?" or "what was wrong in my approach?", because I don't know what to describe. But if there are any people who are used to TDD in C++ (and, probably C#) too, could you please advise me how to do this properly.

Framework recommendations, architecture approaches, plain coding advices - if you are experienced in TDD & C++, please respond.

Answer 1

I think TDD is much harder to do in C++ than C#. The lack of reflection, and the common (and often well-justified) reluctance to rely on dynamic polymorphism (interfaces and in heritance) compared to static polymorphism does make it harder to mock out many classes.

There are some extremely clever unit test frameworks for C++, but the thing that's so clever about them is mainly that they try to bypass the language limitations.

TDD works best in dynamic languages. It's a great way to work in Python. It's doable in C# (which isn't dynamic, but has comprehensive reflection capabilities)

In C++, it's often problematic. That doesn't mean it can't, or shouldn't, be done, but when you do it, expect to have to work a bit harder at it. And sometimes, you may be better off using another approach entirely.