How to make Travis CI to install Python dependencies declared in tests_require?

Question

I have Python package with setup.py. It has regular dependencies declared in install_requires and development dependencies declared in tests_require, e.g. flake8.

I thought pip install -e . or running python setup.py test will also install my development dependencies and they'll be available. However, apparently they're not and I struggle to setup my Travis CI build right.

install:
  - "pip install -e ."
script:
  - "python setup.py test"
  - "flake8"

Build configured as above will fail, because flake8 will not be found as a valid command. I also tried to invoke flake8 from inside of the python setup.py test command (via subprocess), but also without success.

Also I hate the fact that flake8 can't be easily made integral part of the python setup.py test command, but that's another story.

Answer 1

The more direct answer is that pip install will not install tests_require, intentionally separating runtime requirements from test requirements. python setup.py test creates a virtualenv-like environment to run the tests in, un-doing this afterwards. flake8 is thus unavailable once it is done.

Flake8 has setuptools integration and also integrates with pytest if you use that. pytest itself also integrates with setuptools.

Answer 2

I prefer to keep most of the configuration in tox.ini and rely on it to install and run what is to be run. For testing I use pytest (the solution can be modified to use other testing frameworks easily).

Following files are used:

• tox.ini: automates the test
• .travis.yml: instructions for Travis
• setup.py: installation script to install the package to test
• test_requirements.txt: list of requirements for testing

tox.ini

[tox]
envlist = py{26,27,33,34}

[testenv]
commands =
    py.test -sv tests []
deps =
    -rtest-requirements.txt

.travis.yml

sudo: false
language: python
python:
    - 2.6
    - 2.7
    - 3.3
    - 3.4
install:
    - pip install tox-travis
script:
 - tox

test_requirements.txt

Just ordinary requirements file whith what ever you need in there (e.g. flake8, pytest and other dependencies)

You may see sample at https://github.com/vlcinsky/awslogs/tree/pbr-setup.py

The fact it uses there pbr, coverage and coverall is not relevant to my answer (it works with or without pbr).