TST: create unit tests

[aburrell]

Create a framework for unit tests and include an assessment of the coverage.

[KCollins]

@aburrell

• Request: Would you link to a template/example for unit tests in your preferred idiom?
• Q: Could we adapt the code in MWE.ipynb for our tests?

[aburrell]

Most people I work with prefer pytest: https://docs.pytest.org/en/stable/

There are some nice examples there. Here's an example for a module with a simple set of functions (some of the other tests in the package get more complicated): https://github.com/pysat/pysatSpaceWeather/blob/main/pysatSpaceWeather/tests/test_methods_norp.py

You can use examples as a base for unit tests. I usually go through a checklist like this:

• test that the function succeeds at the thing it's supposed to do with default inputs
• test that the function succeeds using all potential alternative inputs
• check that the errors are raised and have the right messages in the right places
• check that the logging/print statements occur at the expected times

[KCollins]

@aburrell - Not sure if this issue is ready to close or not. Obviously the unit test framework is in place, but I don't know how to establish that the set of unit tests is exhaustive. 🤔

Let me know your thoughts. In the meantime, will transfer this to the 4.0 milestone.

[aburrell]

That's what coveralls is for. I try to get my coverage to above 95%, usually, but aim for 100%. Sometimes there are tests in the code that are hard to trigger, that's usually what prevents me in some cases.

However, now that you have unit tests and can see how far you have to go, you can close this issue and create a new one (or multiple ones) aimed at increasing coverage in different areas of the code.

[aburrell]

You can also run coverage locally to see how things look on your local system when you're adding lots of tests and don't want to run the GitHub CI. https://coverage.readthedocs.io/en/7.8.0/cmd.html