Write automated tests

Problem/Motivation

In order for the project to be maintainable enough for the maintainers to feel comfortable opting into security advisory coverage, the project needs automated tests.

Proposed resolution

Write automated tests we can use to verify that changes do not cause functionality to regress.

Remaining tasks

1. Decide what we need to test and update this issue's remaining tasks

User interface changes

Likely none.

API changes

Likely none.

Data model changes

Likely none.