Mugetsu•3y ago

How to enforce usequery as NonNullable

I have a custom hook with infinite query. I check for undefined at the app first render and then it is reused so I know by then, the type should not be undefined. I would like to be able to infer its type without undefined conditionally. Can I do that? How to if so??

export const useAppContext = (enabled = true) =>
  api.appContext.getAppContext.useQuery(undefined, {
    staleTime: Infinity,
    enabled,
    select: (data) => {
      currentRoles = data?.authorisation?.roles ?? []
      return data
    },
  })

export const useAppContext = (enabled = true) =>
  api.appContext.getAppContext.useQuery(undefined, {
    staleTime: Infinity,
    enabled,
    select: (data) => {
      currentRoles = data?.authorisation?.roles ?? []
      return data
    },
  })

4 Replies

Nick•3y ago

The type of what is undefined?

MugetsuOP•3y ago

the type of data will be in this case always the TYPE | undefined. const { data } = useAppContext() I would like it to be: 1st time (app top level) of type -> TYPE | undefined and then force it to be just -> TYPE so I dont have to do checking for undefined or mark chaining of data property with ! as I know at this time it's already in the cache and exists

Nick•3y ago

Ah right, this is a react-query question, and I think the answer is it's not possible react-query just defines that value as possibly undefined, because in theory at any point it could be and typescript is static I guess that might change when suspense becomes a bigger thing

MugetsuOP•3y ago

Alright, I will ask tho at react-query but I see your point.

How to enforce usequery as NonNullable

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