How to get what activity is running android studio

I`m trying to check the flow of my program and to do so i need a way to get the type of a class that is currently running.

I tried searching the web for some info about the subject but as i see most of the examples add a static variable for the active data.

Beside testing the logic of my program I want to test the GUI as well so i will be able to check that after I press a button the correct activity is running.

There isn't much info about testing on Android studio so any help will be highly appreciated (Such as "You are in a completely wrong path, you can test your GUI by...")

Thanks