tanstack-query

Wrap your app in QueryClientProvider with a QueryClient, then call useQuery with a serializable queryKey array and a queryFn that returns a promise. TanStack Query caches the result, deduplicates requests, and refetches stale data automatically.

In onMutate, cancel outgoing queries with cancelQueries, snapshot the current cache via getQueryData, then write the new value with setQueryData. Return the snapshot as context and restore it in onError to roll back on failure.

Yes. useInfiniteQuery handles cursor-based infinite lists with getNextPageParam and fetchNextPage, while regular useQuery with placeholderData set to the previous data keeps paginated views stable between page changes.

staleTime controls how long data is considered fresh before refetching, while gcTime controls how long unused cached data is kept before garbage collection. Setting staleTime higher than gcTime can cause data to be collected while still marked fresh.

The default retry setting causes repeated fetch attempts in tests. Configure the test QueryClient with retry: false and gcTime: Infinity, and always wrap tested hooks in a fresh QueryClientProvider to avoid shared cache state.