Better protect against using lib on wrong board?

[caternuson]

If someone attempts to import this lib:

from adafruit_circuitplayground import cp

on a non-Playground board, it'll throw an import error:

 ImportError: no module named 'adafruit_circuitplayground.cp'

which is potentially confusing.

Suggest updating the conditional: https://github.com/adafruit/Adafruit_CircuitPython_CircuitPlayground/blob/47f848f13f75d2f62d16407edaaf6dd0ec1fc3cc/adafruit_circuitplayground/__init__.py#L9-L12 to add a final else clause at the end to throw a more meaningful exception and message.

[tekktrik]

I think this is a neat idea; out of curiosity, how common is that issue?

[caternuson]

Not common at all. So far at least. It's similar to the using-wrong-neopixel-library issue. It can happen when following links form guides that link to guides that link to guides, etc. The original context was non-Playgorund but at some point can switch to being Playground specific. And code is just being copy pasted.

Thinking message would be something like "board not supported. this lib is for circuit playground boards only"

[tekktrik]

Makes sense to me!

[Neradoc]

Note that any new string would be added to the CPX frozen library build, where we fight for each byte we can get. It might be reasonably small though. Also these tests accept any NRF52 or samd21 anyway ? Is that ok ? Should we instead test board_id ? (if there is no backwards compatibility issue).

[tekktrik]

This change would be a good use case and test of the CI for checking memory that @FoamyGuy is working on, actually.

[tekktrik]

Is this still something we want to do? Just looking through old notifications that were not merged/closed.

[ChrisPappalardo]

working on this issue

[kattni]

After discussion, we've decided to close this issue. We have a couple of options for how to do it, but CI fails on one, and the second adds too much to the library. @caternuson said this issue has not come up since it was filed.