Another PR around 1000 lines, but most of it is copied from pymeasure and adjusted accordingly.

It's good, that we set it up: I already encountered one incompatibility with python 3.10 (I use 3.11).

Open:

• Static Tests
• test coverage
• lining with ruff (in the beginning parallel to flake8? )

lining with ruff (in the beginning parallel to flake8? )

I'd just use ruff, and not flake8 anymore, no sense in duplicating this.
There is a Github Action available for it: https://github.com/chartboost/ruff-action

Also, consider using mamba instead of conda, it should be much faster (https://github.com/mamba-org/setup-micromamba should be the right action)... it's kinda crazy how much time package/env setup is taking in the pymeasure CI jobs.

Great work! I have to go through it later..

Maybe we could exclude the top level init.py (with the versioning code) from coverage. I already excluded the definition files, which follow LECO (leco-protocols and errors), as it is not useful to test these definitions.

I would not ignore the init file, but just specifically ignore that clause for the error condition 👍

except (ImportError, LookupError):  # pragma: no cover

That is more targeted, and the rest of the file remains covered.

For teh leco-protocol, you seem to even give testing instructions (I only briefly skimmed). You don't think this should be tested in pytest? Or does just the coverage checking not work there?

Regarding ruff: should we move that extend-select to the config in pyproject.toml, too, or is there a specific reason why that is specified in the CI config?

I give instructions on how to use these protocol definitions to test an implementation of that protocol.

Testing the protocols has two difficulties:

• how to test abstract methods?
• what advantage do we get? Right now the protocol defines the behavior (signature). With tests, the tests define the behavior.

Re the tests/**/__init__.py files: Those should not be added AFAIK. Why was that necessary, what was the problem here?

Coverage calculated needs them. Otherwise it says 0%...
That's what I tried to say with the commit message.

Regarding ruff: should we move that extend-select to the config in pyproject.toml, too, or is there a specific reason why that is specified in the CI config?

The reason is, that flake was configured that way I. Pymeasure. I just adapted it.

coverage of testing code does not make sense, though, does it? It's the testing code that creates coverage after all?
The only thing that guards against is if some tests are skipped/ignored or inadvertantly not run, but I'm not sure if that's worth it.
I remember pytest docs cautioning against adding init to test folders, but could not quickly find that part.

I give instructions on how to use these protocol definitions to test an implementation of that protocol.

Testing the protocols has two difficulties:

* how to test abstract methods?

* what advantage do we get? Right now the protocol defines the behavior (signature). With tests, the tests define the behavior.

OK, fair enough!

coverage of testing code does not make sense, though, does it? It's the testing code that creates coverage after all? The only thing that guards against is if some tests are skipped/ignored or inadvertantly not run, but I'm not sure if that's worth it. I remember pytest docs cautioning against adding init to test folders, but could not quickly find that part.

Sorry for not being specific enough: Coverage needs init files in the test directory to calculate the coverage of the main source files...
I did not find the original recommendation to add these, but here is an issue: pytest-dev/pytest-cov#401

EDIT: here the suggestion to add init.py files https://stackoverflow.com/questions/47287721/coverage-py-warning-no-data-was-collected-no-data-collected#52044708

I figured it out: You have to install the package editable, then you do not need the init files.

that's probably just a workaround/hack, but at least the problem's avoided. 👍
It seems from this example that our layout should be achievable without init files, and without going to a src layout, but it will be some time before I get around to play around with this locally.
I guess a src-based layout would in general be preferable because it is quicker to surface path/import problems (which can be hidden otherwise, see pytest docs), but I haven't yet tried that out.

I fixed all your points (except the ruff configuration):

• No init.py in test directories
• global init.py is covered with "no cover"
• leco definitions (purely abstract methods or numbers from the leco definition) are not tested
• ruff configuration from CI also in pyproject.toml?

EDIT: I pushed temporarily (changed in a commit, reversed in the next) a broken message file which was (correctly) shown as broken by mypy. So that works as expected.

Thanks for all the work! Feel free to merge!