Add a "status" key to useQuery response

[jgoux]

Hello 👋 ,

I'd like to have a status key returned from useQuery/useMutation so I can easily pattern-match on it to handle every cases (fetching/error/data) exhaustively and explicitly.

Ideally the response type should be a union like :

type UseQueryState<Data, Variables> = { status: "fetching" } |  { status: "success", data?: Data } | { status: "error", error?: CombinedError }

This is how react-query does it. All the other boolean values are just derived from the status as extra helpers.

[JoviDeCroock]

This doesn't really work too well for GraphQL as sub-resolvers, ... can error which doesn't mean that there's no data or that it's fatal for the UI. Furthermore we can have partial/stale dat as well.

[jgoux]

I'm not sure I understand, my example was a simplification but you do return a finite number of possible combination?

[kitten]

The finite number of possible states is actually each permutation of data (none, partial, full), error (none, GraphQL errors, network w/o data), fetching, stale. So all states can coexist and hence a state machine like pattern doesn't make sense, as in, if we build it in we'd just encourage people to ignore some permutations even when they shouldn't 😅

[jgoux]

You can have both data and error? I didn't know that. ^^

Well then I'll continue my chained if conditions I guess! Thanks both of you for the quick feedback!