Unit Tests

[Eonasdan]

This project really needs some unit tests. Let's look at https://vitest.dev to see how difficult it would be to implement.

[Eonasdan]

I have add vitest to the project and built some tests around the DateTime object. This task isn't really "done" as far as having testing around everything but it's a start.

I'm going to leave this open until I add a github action.