Since Vite setup is migrated to user-land, Vitest migration to user-land is now possible. The main motivation to move Vitest to user-land is that users will be able to use it for server code tests as well.

I've done it already once in Vite POCs (#3584) and it required:

• removing all testing deps from the SDK
• removing all Vitest setup from wasp:config plugin
• remove the testing helpers from the SDK and documenting them in the docs