Very cool, I will take a look!

I also had to make a partial Pin interface

We were needing to do something about that probably, however since some drivers do very specific things with Pin we will have to see how far we can take that.

I'm not sure if the chip select pin should be part of the test helper or an independent concern.

A very good question. Since we do that CS "manually" in the drivers, it probably needs to be somehow separated.

I added another, very basic expectation based Pin implementation as well. Works for CS at least.

Using something like testify/mock and mockery might be a better direction for these.