the way you can use vitest with sveltekit is going to improve. As long as it isn't stable (see also https://github.com/nickbreaton/vitest-svelte-kit#stability) it's not suitable as an option in create-svelte.

In the interim, a svelte-adder could be implemented: svelte-add/svelte-add#191

I hear you. It's a bit of a chicken and the egg scenario. Kit is still in beta and I'm thinking more about man-hours spent trying to get Jest working with it as opposed to growing together with Vitest.

I think writing an adder for https://github.com/svelte-add/svelte-add is the best way to solve the chicken-and-egg problem, or if not solve it completely at least get around the largest issue. Things shouldn't go into create-svelte until they're stable, but if there's an unofficial (or semi-official) adder package, people won't have the same expectation of stability. So any errors due to rapidly-moving targets won't reflect badly on Svelte-Kit for people trying it out for the first time. But at the same time, it could be mentioned in the documentation (in the FAQ section, perhaps) as a recommended way to set up unit testing that's simpler than using Jest.

Closing due to low priority to reduce noise. Check out this Discord server for chat about configuring Vitest. 👍

Further discussion and voting #5285