Conditional Commands in tox? (tox, travis-ci, and coveralls)

I have a similar setup with Travis, tox and coveralls. My idea was to only execute coveralls if the TRAVIS environment variable is set. However, it seems this is not so easy to do as tox has trouble parsing commands with quotes and ampersands. Additionally, this confused Travis me a lot.

Eventually I wrote a simple python script run_coveralls.py:

#!/bin/env/python

import os

from subprocess import call


if __name__ == '__main__':
    if 'TRAVIS' in os.environ:
        rc = call('coveralls')
        raise SystemExit(rc)

In tox.ini, replace your coveralls command with python {toxinidir}/run_coveralls.py.

An alternative solution would be to prefix the coveralls command with a dash (-) to tell tox to ignore its exit code as explained in the documentation. This way even failures from coveralls will be ignored and tox will consider the test execution as successful when executed locally.

Using the example configuration above, it would be as follows:

[tox]
envlist = py27

[testenv]
passenv = TRAVIS TRAVIS_JOB_ID TRAVIS_BRANCH
deps =
    pytest
    coverage
    pytest-cov
    coveralls
commands =
    py.test --cov={envsitepackagesdir}/mypackage --cov-report=term --basetemp={envtmpdir}
    - coveralls