Strict type checking and py.typed

[Avasam]

Closes #17

Ref: jaraco/skeleton#143

This is one of the untyped libs used by distutils and setuptools.

[jaraco]

Sadly, this isn't working on mypy under PyPy.

FAILED jaraco/text/__init__.py::mypy - jaraco/text/__init__.py:205: error: Unused "type: ignore[untyped-decorator]...

[jaraco]

Interestingly, it passes for me locally.

Details

 jaraco.text main 🐚 tox -e pypy
.pkg-pypy310: install_requires> python -I -m pip install coherent.licensed 'setuptools>=77' 'setuptools_scm[toml]>=3.4.1'
.pkg-pypy310: _optional_hooks> python '/Users/jaraco/Library/Application Support/pipx/venvs/tox/lib/python3.13/site-packages/pyproject_api/_backend.py' True setuptools.build_meta
.pkg-pypy310: get_requires_for_build_editable> python '/Users/jaraco/Library/Application Support/pipx/venvs/tox/lib/python3.13/site-packages/pyproject_api/_backend.py' True setuptools.build_meta
.pkg-pypy310: build_editable> python '/Users/jaraco/Library/Application Support/pipx/venvs/tox/lib/python3.13/site-packages/pyproject_api/_backend.py' True setuptools.build_meta
pypy: install_package_deps> python -I -m pip install autocommand inflect 'jaraco.context>=4.1' jaraco.functools more_itertools 'mypy<1.19; platform_python_implementation == "PyPy"' 'pathlib2; python_version < "3.10"' 'pytest!=8.1.*,>=6' 'pytest-checkdocs>=2.4' pytest-cov 'pytest-enabler>=3.4' 'pytest-mypy>=1.0.1' 'pytest-ruff>=0.2.1; sys_platform != "cygwin"'
pypy: install_package> python -I -m pip install --force-reinstall --no-deps /Users/jaraco/code/jaraco/jaraco.text/.tox/.tmp/package/36/jaraco_text-4.0.1.dev56+g6a9b9bd06-0.editable-py3-none-any.whl
pypy: commands[0]> pytest
============================================================== test session starts ===============================================================
platform darwin -- Python 3.10.14[pypy-7.3.17-final], pytest-9.0.2, pluggy-1.6.0
cachedir: .tox/pypy/.pytest_cache
rootdir: /Users/jaraco/code/jaraco/jaraco.text
configfile: pytest.ini
plugins: mypy-1.0.1, ruff-0.5, checkdocs-2.14.0, enabler-3.4.0, typeguard-4.4.4, cov-7.0.0
collected 53 items                                                                                                                               

conftest.py ...                                                                                                                            [  5%]
docs/conf.py ...                                                                                                                           [ 11%]
jaraco/text/__init__.py ...........................                                                                                        [ 62%]
jaraco/text/layouts.py .....                                                                                                               [ 71%]
jaraco/text/show-newlines.py ....                                                                                                          [ 79%]
jaraco/text/strip-prefix.py ....                                                                                                           [ 86%]
jaraco/text/to-dvorak.py ...                                                                                                               [ 92%]
jaraco/text/to-qwerty.py ...                                                                                                               [ 98%]
. .                                                                                                                                        [100%]

================================================================ warnings summary ================================================================
conftest.py::mypy
  /opt/homebrew/Cellar/pypy3.10/7.3.17_1/libexec/lib/pypy3.10/configparser.py:694: EncodingWarning: 'encoding' argument not specified.
    encoding = io.text_encoding(encoding)

conftest.py::mypy
  /Users/jaraco/code/jaraco/jaraco.text/.tox/pypy/lib/pypy3.10/site-packages/mypy/modulefinder.py:979: EncodingWarning: 'encoding' argument not specified.
    with open(versions_path) as f:

conftest.py::mypy
  /Users/jaraco/code/jaraco/jaraco.text/.tox/pypy/lib/pypy3.10/site-packages/mypy/build.py:3583: EncodingWarning: 'encoding' argument not specified.
    with open(fnam, "w") as f:

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
====================================================================== mypy ======================================================================
Success: no issues found in 8 source files
================================================================= tests coverage =================================================================
_______________________________________________ coverage: platform darwin, python 3.10.14-final-0 ________________________________________________

Name                           Stmts   Miss  Cover   Missing
------------------------------------------------------------
conftest.py                        6      0   100%
docs/conf.py                      15      0   100%
jaraco/text/__init__.py          165      0   100%
jaraco/text/layouts.py             8      0   100%
jaraco/text/show-newlines.py      10      0   100%
jaraco/text/strip-prefix.py        6      0   100%
jaraco/text/to-dvorak.py           3      0   100%
jaraco/text/to-qwerty.py           3      0   100%
------------------------------------------------------------
TOTAL                            216      0   100%
=================================================== 53 passed, 3 warnings in 87.69s (0:01:27) ====================================================
  pypy: OK (99.52=setup[10.55]+cmd[88.97] seconds)
  congratulations :) (99.58 seconds)

[jaraco]

My guess is the untyped-decorator was added in a later mypy, but since mypy dropped support for PyPy (python/mypy#20454), it is now no longer compatible.

[jaraco]

It's not that the PyPy issue. And if it was, that wouldn't have explained why mine passed locally. I did try installing mypy<1.19 in my CPython install, but that had no effect (still passes).

[jaraco]

Oh, silly me. I wasn't on the PR branch. After switching to the PR branch, I'm able to replicate the failure.

[jaraco]

I tried adding in another ignore ("unused-ignore"), but now there's a new mypy error (still PyPy only):

jaraco/text/__init__.py:205: error: Untyped decorator makes function "is_decodable" untyped  [misc]
jaraco/text/__init__.py:205: note: Error code "misc" not covered by "type: ignore" comment

[Avasam]

If it's a pypy-only failure, that's odd.

But even if it's not, I'll take this opportunity to mention that I've also been pushing to stop running mypy on pypy for various reasons: flaky tests, randomly not matching an import-based error (likely due to differing dependencies), sporadic build failures, taking more CI time for a static non-runtime check that is already covered, etc: jaraco/skeleton#187

[jaraco]

In ab1de64, I suppressed those additional classes and now the tests are passing on mypy too.

[jaraco]

I've been pushing to stop running mypy on pypy

Probably a wise choice. I'd like to avoid making that change a blocker for this change, so I'll follow up on that later, now that I've found a workaround.

[Avasam]

It's funny you can ignore unused-ignore, I seem to remember this was causing a self-referential issue a long time ago !

[Avasam]

Thanks for the thorough review! Now that this is merged, my other 3 PRs have conflicts, but they are 3 suggestions for the same core issue. I'll let you think about your preferred approach before fixing conflicts.