Re: [PATCH 2/6] test: Add linting of Python test scripts

[Stefano Brivio <sbrivio@redhat.com>]

On Wed,  1 Oct 2025 19:51:58 +1000
David Gibson <david@gibson.dropbear.id.au> wrote:

> We currently have one test moved to the new exeter based framwork written
> in Python.  We plan to add many more, so add linting (flake8) and type
> checking (mypy) of those scripts.  This can be invoked manually with
> "make flake8" or "make mypy" in test/, and is also added to the static
> checkers test set.

I never used a Python linter, so I'm not sure if it's as bad as Go or
Rust linters taking the whole poetry away, as it happened for instance
in my most recent experience with 'cargo fmt':

  https://github.com/AsahiLinux/muvm/compare/68094c02c19b6f5d5e3def6d29379c1244c9a5e4..9af11c334a1ce37f533c056d982f8608c8d80d27#diff-e1a95ce380b9a8a317f97cccce1cbfd3dccd343dc62169ed1340208ab304fab9L106

  https://github.com/AsahiLinux/muvm/pull/111#discussion_r1863551727
  (you need to click around before you get to it, no idea how to share
  a proper link that opens that comment right away)

Maybe with Python it's not as annoying? I don't have a strong
preference against this, I just wanted to raise a possible downside.

In general, my thought is that coding style serves a purpose, and it's
used by humans for humans, so it's flexible, with exceptions, and
reasons behind it and behind those exceptions.

If we just pass everything through a linter, well, except for the
purposes of revision control, we don't really need a coding style?

> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
> ---
>  test/Makefile                 | 14 +++++++++++++-
>  test/build/build.py           |  5 +++--
>  test/build/static_checkers.sh |  6 +++++-
>  3 files changed, 21 insertions(+), 4 deletions(-)
> 
> diff --git a/test/Makefile b/test/Makefile
> index 69987d0b..2637e0ed 100644
> --- a/test/Makefile
> +++ b/test/Makefile
> @@ -8,6 +8,8 @@
>  BATS = bats -j $(shell nproc)
>  EXETOOL = exeter/exetool/exetool
>  WGET = wget -c
> +FLAKE8 = flake8
> +MYPY = mypy --strict
>  
>  DEBIAN_IMGS = debian-8.11.0-openstack-amd64.qcow2 \
>  	debian-10-nocloud-amd64.qcow2 \
> @@ -65,11 +67,15 @@ LOCAL_ASSETS = mbuto.img mbuto.mem.img podman/bin/podman QEMU_EFI.fd \
>  ASSETS = $(DOWNLOAD_ASSETS) $(LOCAL_ASSETS)
>  
>  EXETER_PYPATH = exeter/py3
> +EXETER_PYTHON = build/build.py
>  EXETER_BATS = smoke/smoke.sh.bats \
> -	build/build.py.bats build/static_checkers.sh.bats
> +	$(EXETER_PYTHON:%=%.bats) build/static_checkers.sh.bats
>  BATS_FILES = $(EXETER_BATS) \
>  	podman/test/system/505-networking-pasta.bats
>  
> +# Python test code (for linters)
> +PYPKGS = $(EXETER_PYTHON)
> +
>  CFLAGS = -Wall -Werror -Wextra -pedantic -std=c99
>  
>  assets: $(ASSETS)
> @@ -130,6 +136,12 @@ medium.bin:
>  big.bin:
>  	dd if=/dev/urandom bs=1M count=10 of=$@
>  
> +flake8: pull-exeter
> +	PYTHONPATH=$(EXETER_PYPATH) $(FLAKE8) $(PYPKGS)
> +
> +mypy: pull-exeter
> +	PYTHONPATH=$(EXETER_PYPATH) $(MYPY) $(PYPKGS)
> +
>  $(EXETER_BATS): %.bats: % $(EXETOOL)
>  	PYTHONPATH=$(EXETER_PYPATH) $(EXETOOL) bats -- $< > $@
>  
> diff --git a/test/build/build.py b/test/build/build.py
> index e49287c9..e3de8305 100755
> --- a/test/build/build.py
> +++ b/test/build/build.py
> @@ -18,11 +18,12 @@ import os
>  from pathlib import Path
>  import subprocess
>  import tempfile
> -from typing import Iterable, Iterator
> +from typing import Iterator
>  
>  import exeter
>  
> -def sh(cmd):
> +
> +def sh(cmd: str) -> None:
>      """Run given command in a shell"""
>      subprocess.run(cmd, shell=True)
>  
> diff --git a/test/build/static_checkers.sh b/test/build/static_checkers.sh
> index 42806e79..228b99ae 100755
> --- a/test/build/static_checkers.sh
> +++ b/test/build/static_checkers.sh
> @@ -21,6 +21,10 @@ exeter_set_description cppcheck "passt sources pass cppcheck"
>  exeter_register clang_tidy make -C .. clang-tidy
>  exeter_set_description clang_tidy "passt sources pass clang-tidy"
>  
> -exeter_main "$@"
> +exeter_register flake8 make flake8
> +exeter_set_description flake8 "passt tests in Python pass flake8"
>  
> +exeter_register mypy make mypy
> +exeter_set_description mypy "passt tests in Python pass mypy --strict"
>  
> +exeter_main "$@"

-- 
Stefano