Unit Test Framework?

The repo consists of two scripts right now which define a clear and concise interface and a working implementation. It looks like my PR for swapping the internal datastructure was the first PR to require any testing. If there are any other changes planned, would it make sense to pick a unit test framework to make sure contributors don't break existing functionality?

Read the repository’s two scripts and review the internal data-structure change that first required testing. Compare how the existing Python implementation could be exercised by a unit-test framework; the issue does not identify a framework, test files, or a defined completion condition, so those would need to be established before implementation.

Written by the indexing model from the issue text.