[Feature] - Vitest test suite for utility functions

[barrymun]

What feature would you like to see?

Problem

It would be very useful to be able to test the code, and also have it be tested automatically.

Solution

Add vitest package and allow developers to run a test suite whenever required, and also have it run before commit and on workflow PRs.

Component tests would also be useful, but it might be better to split the workload and add this functionality as a separate PR.