Maybe it's only difficult to test end-to-end? I would assume there's code in there that's algorithm-like. Give it these inputs, it should return these outputs

Maybe it's only difficult to test end-to-end? I would assume there's code in there that's algorithm-like. Give it these inputs, it should return these outputs. If so, it should be possible to isolate that code and test it. But, I dunno, I haven't looked at the source code. It might be very difficult to maintain.