The result of getServerSnapshot should be cached to avoid an infinite loop

[intrepidsg]

Hey, @nikgraf , thanks for the updated react connector! I was mucking around with useY in Next and got this error from useSyncExternalStore(_, _, getServerSnapshot). According to react docs it seems to stem from the mutability of the return data from that parameter.

(https://react.dev/reference/react/useSyncExternalStore#im-getting-an-error-the-result-of-getsnapshot-should-be-cached)

This can be avoided by bypassing SSR but I found that using

() => {
    const data = yData.toJSON();
    if (equalityDeep(prevDataRef.current, data)) {
        return prevDataRef.current;
    } else {
        prevDataRef.current = data;
        return prevDataRef.current;
    }
}

For both parameters was able to work with SSR.

[nikgraf]

Great find, thanks!

Interested to create a PR?