Support urql ssr prefetching without suspense

[danielr18]

In order to use async atoms without Suspense, we can wrap them with the loadable API.

The issue with the urql integration using the loadable API is that the resultAtom value is always a promise, so the loadable atom value will always be { state: 'loading' } during SSR even if the data is prefetched.

If it's possible to get a sync snapshot during SSR (perhaps by passing a suspense: false arg), then resultAtom could be the prefetched result instead of a promise. I imagine something similar to react urql useQuery hook
https://github.com/FormidableLabs/urql/blob/bea39c2eb4a93669f5d1d4ee775dfc45cf56a39d/packages/react-urql/src/hooks/useQuery.ts#L99

FYI: SSR prefetching works with jotai query and loadable API.

[dai-shi]

Hi, thanks for opening this up.
This is slightly related with #1068 and I'm now thinking of redesigning query&urql integrations for various reasons:

• suspense oriented API should just return Data, but that doesn't cover all use cases.
• there's some inconsistency between jotai/query and jotai/urql API design, due to it.
• implementation is very hard each and not very maintainable. it should be a thin wrapper.
• the current versioning can confuse people. React Query v4 #1312 (reply in thread)

This will be a big change, and we should give migration path. It's on my action items. I'll ask for help when something is ready to play with.