[TIP] tox and coverage across multiple envs

[Andrew Dalke]

(Was deep in a code rewrite and put off worrying about cross-env testing for a few weeks.)

On Aug 10, 2011, at 12:29 PM, Michael Foord wrote:
> On 09/08/2011 09:20, Andrew Dalke wrote:
>> [snip...]
>> 
>> Also, when the tests find an error, I find that it's hard
>> to get to a reproducible state because each of my environments
>> has different environment variables. (LD_LIBRARY_PATH, path
>> to license file, etc.) Is there any way to do something like
>> 
>> tox -e py26-rd201106 --run python
>> 
>> and get me into that specific Python along with the right
>> environment setup? Or is there some other way to handle this?
> Perhaps:
> 
>   .tox/py26-rd201106/bin/python

That unfortunately doesn't set the environment variables

% .tox/py25-ob223/bin/python
Python 2.5.4 (r254:67916, Jun 24 2010, 21:47:25) 
[GCC 4.2.1 (Apple Inc. build 5646)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import openbabel
Traceback (most recent call last):
 File "<stdin>", line 1, in <module>
ImportError: No module named openbabel
>>> 

If you look in my tox.ini you'll see I set up a number of environment variable


% fgrep -A 8 "[testenv:py25-ob223]" tox.ini
[testenv:py25-ob223]
basepython=/Users/dalke/envs/py25-ob223/bin/python2.5
setenv=
 TOX_CHEMFP_TEST=py25,x32,ob223
 BABEL_LIBDIR=/Users/dalke/envs/openbabel-2.2.3/lib/openbabel/2.2.3
 BABEL_DATADIR=/Users/dalke/envs/openbabel-2.2.3/share/openbabel/2.2.3
 DYLD_LIBRARY_PATH=/Users/dalke/envs/openbabel-2.2.3/lib
 PYTHONPATH=/Users/dalke/envs/py25-ob223/lib/python2.5/site-packages/

I need to set most of them in order to run

% env \
?   BABEL_LIBDIR=/Users/dalke/envs/openbabel-2.2.3/lib/openbabel/2.2.3 \
?   BABEL_DATADIR=/Users/dalke/envs/openbabel-2.2.3/share/openbabel/2.2.3 \
?   DYLD_LIBRARY_PATH=/Users/dalke/envs/openbabel-2.2.3/lib \
?   PYTHONPATH=/Users/dalke/envs/py25-ob223/lib/python2.5/site-packages/ \
?   .tox/py25-ob223/bin/python
Python 2.5.4 (r254:67916, Jun 24 2010, 21:47:25) 
[GCC 4.2.1 (Apple Inc. build 5646)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import openbabel
>>> 

None of the packages I deal with are on PyPI, and they are layers
on top of C++ packages which are installed separately. For example,
the first three environment variables in my `env` are requirements
of the C++ code. In another case I need to point to a license file
to use a proprietary package, and I want to test if I handle the
case when the license environment variable isn't present.

I thought about having

  tox -e py26-rd201106 --shell

which gives me the Python prompt for that environment, but I want
more than that. My package includes a few command-line tools. If
there's something wrong with the tests for that tool then I would
like to do

   tox -e py26-rd201106 --run ob2fps --options --to --my tool

so I can debug it more effectively inside the context of that
environment.

(However, since my command-line tools are basically:

try:
 from chemfp.commandline.ob2fps import main()
 main()
except KeyboardInterrupt:
 raise SystemExit()

then this is not critical as I could make the right call
from the Python shell, as

 from chemfp.commandline.ob2fps import main()
 main("ob2fps --options --to --my tool".split())


)


				Andrew
				dalke at dalkescientific.com