I have written these tests (just one as of now) for my own gameboy emulator, this repo has a script to build them, or you can get them from the release tab on the right
Caution
I have written these to be used on an emulator, altough these should also work on hardware, I will not be responsible for the damage it might cause
sprite-scroll-x, this one put three sprites on the screen, all of them should scroll by one pixel after every frame (using vblank interrupts), they are divided in two rows, one by itself, and two in a row
To build a test run ./build.sh testname, for example, ./build.sh sprite-scroll-x. To clean generated files except the rom, run ./build.sh clean.
If you are running Nix you can do nix develop . to get the dev environment installed, otherwise you'll have to manually download the rgbds tools