[py-dev] hook ideas for better use/abuse of txspecs and distribution

[holger krekel]

On Wed, Jul 22, 2009 at 12:33 +0200, Ronny Pfannschmidt wrote:
> > In the --tx specifciation one could say e.g. 
> > 
> >     popen//python=python2.5//virtualenv=docutils-0.5,mercurial-1.2
> > 
> > and a pytest_virtualenv plugin could take it, call virtualenv
> > and eventually start up a gateway with the venv/bin/python. 
> 
> ok, how would i generate sets of txspec declarations, 

> cause i want to combine multiple arguments in order to generate the python versions and the package versions
 
i guess by implementing a ``pytest_configure(config)`` hook to
add a few txspecs.  We need to extend the API to the
config object for that, currently it's readonly. Maybe: 

    def pytest_configure(config):
        # access your custom plugin options to 
        # determine which combis to generate 
        config.setvalue('tx', ['spec1', 'spec2', ...])
 
> > > howevers users should be free to generate own gateways to custom set up
> > > things like virtualenvs on local or remote computers and be able to
> > > combine txspecs with own options
> > 
> > To get started, i would first try to get things working with
> > popen, then extend to handle remote places - would you want
> > to automatically install virtualenv there and/or require 
> > setuptools, btw?   

i presume it makes sense to you to first try popen. 

> > > 2. pytest_select_gateways(test, list of gateways) -> list of gateways
> > > 
> > > this hook is supposed to select the gateways each test is supposed to
> > > run on
> > 
> > something like this could make sense.  It's a second step, i'd think, 
> > though. 
> i would certainly need it
> for example tests for mercurial would hardly work in a virtualenv thats
> only only set up for bazaar

you could still skip the tests late-bound but i can see you want
to avoid even trying tests in unfitting environments. 
The issue here is to have a somewhat higher level API for 
what you call "list of gateways" because the raw low-level 
execnet-gateways are not fitting.  you rather want something
where you have structured access to the "test nodes", their
txspecs etc. and this requires a bit of refactoring. 

> > Can you imagine working on a branch to try implement these hooks? 
> > I am willing to help/review. 
> sure

fine.  please add a bitbucket diff-email 
service to py-svn at codespeak.net then. 

best,
holger

> >  
> > 
> > > the default implementation should pass a test to all of them or
> > > distribute them reasonable
> > > the api for this one probably needs a few more idea since i think my
> > > initial proposal is not adequate for all uses
> > 
> > yes, working from concrete uses (a pytest_virtualenv
> > plugin) makes sense.  
> > 
> 
> 

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