Nanostores used in SSR

[azure sable]

Are nanostores safe to use in the server during SSR ?
Recently this post about zustand for RSC and SSR got a lot of traction.https://github.com/pmndrs/zustand/discussions/2200
And I'm wondering if nanostores have the same issues.

Will the stores be cached due to "hot" serverless functions, resulting is users receiving the wroung UI ?

[deep pulsar]

With nanostores you really need to use a framework as they don't really work with just .astro components.

See the FAQ here: https://docs.astro.build/en/recipes/sharing-state-islands/#why-nano-stores

[drifting ingot]

You can use them in .astro but the question about if they are cached in hot functions is valid, and I'd gues they would be

thats some good insight

a clientside nanostore wouldnt have this issue though and I think thats the typical use

[azure sable]

I mostly care about the "hot functions" issue. Here's what i have.

1. Middleware populates locals.user with {userId: '1'}
2. In a top level layout i read from locals.user and sto $store.set(locals.user)
3. Somewhere nested inside this page a React component exists that will read the user from the store during SSR by doing useStore($store)
4. Later I do something similar for client side but this should not matter.

So my question is if 2. and 3 are affected due to hot functions because the store is a global variable

[umbral quest]

I'm also looking for a SSR global store safe way

https://github.com/nanostores/nanostores/issues/80

[drifting ingot]

<@&1129102257422610512> anyone have any insight?

https://discord.com/channels/830184174198718474/1205354265749622794

[normal kiln]

This particular idea won't work because the server may interleave the processing of multiple requests, and nanostore is not contextual

You can implement a contextual store to use Nanostores in that scenario, but it is not available out of the box

Within Node and Bun you wouldn't even need to pass a scope around or anything. That is built into the runtime propagating across every function boundary

[umbral quest]

I did not understood the last part about Node and bun that mean i can safely use the stores in SSR?

[normal kiln]

No, that means you can implement a store that is safe to use on SSR that has all the same API, without having to pass around a scope or reference as proposed on the issue

[azure sable]

Any hints on how to implement a contextual store ? Will AsyncLocalStorage be an appropriate solution ?

[azure sable]

So i created this PR https://github.com/panteliselef/astro-with-clerk-auth/pull/65 seems like it works

[normal kiln]

Just to be sure that you are aware of it. This restricts the possible runtimes that can use your library to just Node and Bun, possibly just Node.

If that is fine to you, go ahead 🙂