Fix and add CI job for packaging

[iFreilicht]

When trying to use this plugin, I found a few issues that this PR resolves:

TLDR:

I fixed two things and added two CI jobs to make your life easier. See https://github.com/iFreilicht/pylint_flask_sqlalchemy/actions/runs/2028803993

You can also download the built wheel and tar.gz distributions there.

Issues

1. The tests directory is installed as an additional package, breaking linting on all my tests

After installing this plugin, the errors relating to flask_sqlalchemy were fixed, but I got a new issue:

$ python3.8 -m pylint -E modules tests tools updater
************* Module tests
tests/__init__.py:1:0: F0010: error while code parsing: Unable to load file tests/__init__.py:
[Errno 2] No such file or directory: 'tests/__init__.py' (parse-error)
************* Module a_special_tool
tools/a_special_tool/a_special_tool.py:23:0: E0611: No name 'test_special_tool' in module 'tests' (no-name-in-module)
tools/a_special_tool/a_special_tool.py:23:0: E0401: Unable to import 'tests.test_special_tool' (import-error)

The reason for these is that pylint_flask_sqlalchemy actually installs two packages:

$ pip uninstall pylint_flask_sqlalchemy
Found existing installation: pylint-flask-sqlalchemy 0.2.0
Uninstalling pylint-flask-sqlalchemy-0.2.0:
  Would remove:
    /home/<long-path>/.venv/lib/python3.8/site-packages/pylint_flask_sqlalchemy-0.2.0.dist-info/*
    /home/<long-path>/.venv/lib/python3.8/site-packages/pylint_flask_sqlalchemy/*
    /home/<long-path>/.venv/lib/python3.8/site-packages/tests/*
Proceed (Y/n)? n

Because tests is now an installed package in my venv, python will consider it first when searching for the tests module during import, meaning pylint tries to lint that, but fails.

2. Building a wheel with build builds an empty wheel

Because there was no build process documented but I saw a pyproject.toml, I thought I could use build to debug the issue myself. As it turns out, that builds an empty wheel:

$ python -m build
# Lots of output, but this seemed to work fine
$ python -m check_wheel_contents dist/*.whl
dist/pylint_flask_sqlalchemy-1.0.0rc0-py3-none-any.whl: W007: Wheel library is empty
dist/pylint_flask_sqlalchemy-1.0.0rc0-py3-none-any.whl: W008: Wheel is empty

3. No CI job for building

This is not really an issue per se, but it might help you get started with the distribution job you mention in #13. As an additonal resource, this github actions config should help you out.

Fix explanation

This was fixed by explicitly setting packages = pylint_flask_sqlalchemy in setup.cfg. After downloading the built wheel from the finished github workflow or installing directly through git, you can see the difference:

$ pip install git+https://github.com/iFreilicht/pylint_flask_sqlalchemy.git@master
# Lots of output
$ pip uninstall pylint_flask_sqlalchemy
Found existing installation: pylint-flask-sqlalchemy 1.0.0rc0
Uninstalling pylint-flask-sqlalchemy-1.0.0rc0:
  Would remove:
    /home/felix/NavVis/epicshelter/.venv/lib/python3.8/site-packages/pylint_flask_sqlalchemy-1.0.0rc0.dist-info/*
    /home/felix/NavVis/epicshelter/.venv/lib/python3.8/site-packages/pylint_flask_sqlalchemy/*
Proceed (Y/n)?

I also added a job to the CI pipeline to check for empty wheels the way I did to avoid a potential future regression.