Re: [PATCH v2 00/16] python: add mypy support to python/qemu

[John Snow <jsnow@redhat.com>]

On 6/2/20 5:51 PM, Eric Blake wrote:
> On 6/2/20 4:45 PM, John Snow wrote:
>> Requires: 20200602194844.15258-1-jsnow@redhat.com
> 
> I don't know if patchew understand that, or if it requires:
> 
> Based-on: 20200602194844.15258-1-jsnow@redhat.com
> 
>>
>> This series is extracted from my larger series that attempted to bundle
>> our python module as an installable module. These fixes don't require
>> that,
>> so they are being sent first as I think there's less up for debate in
>> here.
>>
>> This requires my "refactor shutdown" patch as a pre-requisite.
>>
>> "v2":
>> - This version supports iotests 297
>> - Many patches merged by Phil are removed
>> - Replaces iotests.py type aliases with centralized ones
>>    (See patch 2)
>> - Imports etc are reworked to use the non-installable
>>    package layout instead. (Mostly important for patch 3)
>>
>> Testing this out:
>> - You'll need Python3.6+
>> - I encourage you to use a virtual environment!
>> - You don't necessarily need these exact versions, but I didn't test the
>>    lower bounds, use older versions at your peril:
>>    - pylint==2.5.0
>>    - mypy=0.770
>>    - flake8=3.7.8
>>
>>> cd ~/src/qemu/python/
>>> flake8 qemu
>>> mypy --strict qemu
>>> cd qemu
>>> pylint *.py
>>
>> These should all 100% pass.
>>
>> ---
>>
>> Open RFC: What's the right way to hook this into make check to prevent
>> regressions?
> 
> We recently added iotest 297 in group meta; is there a way to run
> './check -g meta' alongside the other iotests that 'make check' already
> triggers?
> 

If we want to distribute any of this code independently of qemu.git (And
I think we do), I think relying on the iotests infrastructure will hurt
more than it will help.

I think I should try to maintain some independence of this folder from
the rest of the QEMU base; so it should be able to run the linting tests
under its own power.

(So, I guess, a Makefile?)

but there's further problems: this infrastructure is 3.6+ only, but the
build system only requires 3.5+. It has to be an optional testing target
that executes only when it's possible to. It also requires additional
dependencies not checked for in configure -- mypy, pylint, and flake8.

I am wondering if there's a nice way to create a check target that
builds a virtual environment with pinned dependencies, and then uses
that to run the lint tests. As long as the machine you're running on has
at least python3.6+ it should be able to run the tests.

I just don't really have a plan yet...

--js