Write unit tests

[everettraven]

There are currently no unit tests 😲 !

Now that the project is in a good place in terms of functionality it's time to start writing some unit tests. This will be super useful for helping to identify areas of the code that need to be refactored to have good testability and overall improve the code base.

It's probably best to start one file at a time and if it needs tests, write the unit tests for it.

Some useful information for this might be https://carlosbecker.com/posts/teatest/ which gives some insight on how to test bubbletea applications