Unittesting

Introduction

Our python-package libranet_logging comes with a series of tests to check the validity of our code. Some are unittests, others are full integration-tests. The distinction between the several types of tests is of lesser importance.

However we try to minimize the amount of mocking and/or patching. The test-framework we use is pytest.

• https://docs.pytest.org/en/latest/

• https://docs.pytest.org/en/latest/goodpractices.html#test-discovery

• https://pytest-cov.readthedocs.io/en/latest/

Pytest is an extensible framework, and has a whole series of addons and plugins available on PyPi.

You just can pip-install these packages:

<env-dir>/bin/pip install pytest pytest-cov pytest-flask pytest-mccabe pytest-mock

Note

Since the tests are importing the code of libranet_logging, this package needs be installed in a virtualenv, together with all its dependencies. See installation.

Re-usable test-fixtures

For our package, we have several application-specific test-fixtures in tests/conftest.py:

# pylint: disable=missing-function-docstring
"""conftest.py - custom pytest-plugins.

For more information about conftest.py, please see:

 - https://docs.pytest.org/en/latest/writing_plugins.html
 - https://pytest-flask.readthedocs.io/en/latest/tutorial.html

"""
import os
import pathlib

import pytest


@pytest.fixture(scope="session")
def tests_dir():
    tests_dir_ = os.path.dirname(os.path.realpath(__file__))
    return pathlib.Path(tests_dir_)


# @pytest.fixture(scope="session")
# def pkg_dir():
#     pkg_dir_ = pkg_resources.resource_filename("libranet_logging", "")

#     return pl.Path(pkg_resources.files("libranet_logging") / "etc/logging.yml")
#     return pathlib.Path(pkg_dir_)


@pytest.fixture(scope="function")
def env(tmpdir):
    var_dir = tmpdir.mkdir("var")
    var_log_dir = var_dir.mkdir("log")
    # var_run_dir = var_dir.mkdir('run')
    # var_tmp_dir = var_dir.mkdir('tmp')

    # override any existing env-variable
    os.environ["PYTHON_LOG_DIR"] = str(var_log_dir)
    return tmpdir

Run tests

Run pytest via:

> cd <env-dir>
> bin/pytest src/libranet_logging/

> cd <env-dir>src/libranet_logging
> pytest

 (libranet) wouter@midgard: <env-dir>src/libranet_logging >  make py

  platform linux -- Python 3.5.5, pytest-3.5.0, py-1.5.3, pluggy-0.6.0
  rootdir: /opt/miniconda/envs/libranet/src/libranet_logging, inifile: setup.cfg
  plugins: xdist-1.22.2, tap-2.2, forked-0.2, flask-0.10.0, flake8-1.0.0, cov-2.5.1, celery-4.0.2
  collected 15 items

  ========== test session starts =====================
  tests/test_cli.py .
  tests/test_filters.py ....
  tests/test_logconfig.py ........
  tests/test_loglevel.py ..
  ========== 15 passed in 0.33 seconds ===============

Run tests with code-coverage

> pytest --cov=libranet_logging --cov-report html .