These tests are included here for convenience, I (chrisd1100) am not responsible for any of this hard work in any way. The good people at http://wiki.nesdev.com/ and the associated forums (https://forums.nesdev.com/) have made all this possible.
I want to give a special shout-out to blargg (Shay Green): He is responsible for the majority of the important tests in this repo, and without his hard work NES emulators as you know them today would be much less robust and fall short of delivering that quality nostalgia you've come to expect. Thanks blargg!