Unitest Atmega328p Library

I'm currently doing my library for ATMega328p base on Arduino functions in pur C.

I just started today I have only 4 functions so please be cool with it.

My Question is how can I create unitest please?

As you know the compilator must be AVR-GCC in my case. Do you have any idea how can I create and run unitest for this lib please?

Thank you for your help