Test Drive Devlopment with UE4(Deal with complicated/ugly code)

Hello everyone…

I am facing a lot of problems is when work on a big complicated system and I had to keep adding some extra features to it. Even if I start in a clean and planned manner, after some development cycles my code turns complicated and ugly.

A friend of mine advised me to use Test drive development approach. I am relatively very new to the concept; just started reading about it yesterday. So has any one of here used it with unreal C++?
I have a book on TDD with C++ but which uses Google Mock for testing. I think things are different in Unreal compared to C++ so has any here used TDD with UE4? Are they any frameworks what support UE4 good?