Currently, rustcast has no tests to ensure code functionality.

I'm not very sure how to add good tests but rustcast needs tests since there are more contributors now, adding tests might be a good idea.

Ideally someone from @RustCastLabs/rustcast-dev should take this but if anyone else is willing to tackle it, go ahead.

So far the following items should have tests in my opinion:

• AppIndex struct related methods / factory functions
• Debouncer
• File search
• AppCommand (turning into Function)
• App discovery / Macos specific APIs as much as possible
• Calculator & "is_url_like" & unit conversions

Feel free to suggest more, since this definetly lacks a lot of the places that would need tests.