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https://github.com/vercel/swr/blob/14956a840ac9b75fe321bf846...
so if I check `isLoading` in my component then typescript isn't able to narrow/refine the type to something more specific since it isn't a sum type.
While with react-query, it's a proper sum type that can be differentiated by checking `isLoading`.
The type is actually quite long so here's just a bit
export type QueryObserverResult =
https://github.com/TanStack/query/blob/9b21609350d9ad41faf5c...
The key point in the type above is `isLoading: true` and `data: undefined`, which means if I check `isLoading === true`, then typescript knows the data is not available.
SWR doesn't provide these guarantees.