Especially for embedded work (but for regular software too!) I've bought into the "sans-io pattern" for a lot of the software i write anymore
https://sans-io.readthedocs.io/how-to-sans-io.html
Keeping all of the actual hardware/network/io interface code separate really makes writing unit tests and porting to different computers much simpler
I do something similar. I have all my esp/idf code in one crate and all my business logic in a separate crate. The business crate has no dependencies that won’t compile/run on the host. This is where all my tests live.
[flagged]
This is good advice however it should be noted that many of espressif's other purely software components depend on esp-hal, so you still want it to compile if you use any of espressif's provided components.