TanStackQuery v5
Framework
Version

TypeScript

Solid Query is written in TypeScript to make sure the library and your projects are type-safe!

Things to keep in mind:

  • Types currently require using TypeScript v4.7 or greater
  • Changes to types in this repository are considered non-breaking and are usually released as patch semver changes (otherwise every type enhancement would be a major version!).
  • It is highly recommended that you lock your solid-query package version to a specific patch release and upgrade with the expectation that types may be fixed or upgraded between any release
  • The non-type-related public API of Solid Query still follows semver very strictly.

Type Inference

Types in Solid Query generally flow through very well so that you don't have to provide type annotations for yourself

tsx
import { createQuery } from '@tanstack/solid-query'

const query = createQuery(() => ({
  queryKey: ['number'],
  queryFn: () => Promise.resolve(5),
}))

query.data
//    ^? (property) data: number | undefined

import { createQuery } from '@tanstack/solid-query'

const query = createQuery(() => ({
  queryKey: ['number'],
  queryFn: () => Promise.resolve(5),
}))

query.data
//    ^? (property) data: number | undefined

typescript playground

tsx
import { createQuery } from '@tanstack/solid-query'

const query = createQuery(() => ({
  queryKey: ['test'],
  queryFn: () => Promise.resolve(5),
  select: (data) => data.toString(),
}))

query.data
//    ^? (property) data: string | undefined

import { createQuery } from '@tanstack/solid-query'

const query = createQuery(() => ({
  queryKey: ['test'],
  queryFn: () => Promise.resolve(5),
  select: (data) => data.toString(),
}))

query.data
//    ^? (property) data: string | undefined

typescript playground

This works best if your queryFn has a well-defined returned type. Keep in mind that most data fetching libraries return any per default, so make sure to extract it to a properly typed function:

tsx
const fetchGroups = (): Promise<Group[]> =>
  axios.get('/groups').then((response) => response.data)

const query = createQuery(() => ({
  queryKey: ['groups'],
  queryFn: fetchGroups,
}))

query.data
//    ^? (property) data: Group[] | undefined

const fetchGroups = (): Promise<Group[]> =>
  axios.get('/groups').then((response) => response.data)

const query = createQuery(() => ({
  queryKey: ['groups'],
  queryFn: fetchGroups,
}))

query.data
//    ^? (property) data: Group[] | undefined

typescript playground

Type Narrowing

Solid Query uses a discriminated union type for the query result, discriminated by the status field and the derived status boolean flags. This will allow you to check for e.g. success status to make data defined:

tsx
const query = createQuery(() => ({
  queryKey: ['number'],
  queryFn: () => Promise.resolve(5),
}))

if (query.isSuccess) {
  const data = query.data
  //     ^? const data: number
}

const query = createQuery(() => ({
  queryKey: ['number'],
  queryFn: () => Promise.resolve(5),
}))

if (query.isSuccess) {
  const data = query.data
  //     ^? const data: number
}

typescript playground

Typing the error field

The type for error defaults to Error, because that is what most users expect.

tsx
const query = createQuery(() => ({
  queryKey: ['groups'],
  queryFn: fetchGroups,
}))

query.error
//    ^? (property) error: Error | null

const query = createQuery(() => ({
  queryKey: ['groups'],
  queryFn: fetchGroups,
}))

query.error
//    ^? (property) error: Error | null

typescript playground

If you want to throw a custom error, or something that isn't an Error at all, you can specify the type of the error field:

tsx
const query = createQuery<Group[], string>(() => ({
  queryKey: ['groups'],
  queryFn: fetchGroups,
}))

query.error
//    ^? (property) error: string | null

const query = createQuery<Group[], string>(() => ({
  queryKey: ['groups'],
  queryFn: fetchGroups,
}))

query.error
//    ^? (property) error: string | null

However, this has the drawback that type inference for all other generics of useQuery will not work anymore. It is generally not considered a good practice to throw something that isn't an Error, so if you have a subclass like AxiosError you can use type narrowing to make the error field more specific:

tsx
import axios from 'axios'

const query = createQuery(() => ({
  queryKey: ['groups'],
  queryFn: fetchGroups,
}))

query.error
//    ^? (property) error: Error | null

if (axios.isAxiosError(query.error)) {
  query.error
  //    ^? (property) error: AxiosError
}

import axios from 'axios'

const query = createQuery(() => ({
  queryKey: ['groups'],
  queryFn: fetchGroups,
}))

query.error
//    ^? (property) error: Error | null

if (axios.isAxiosError(query.error)) {
  query.error
  //    ^? (property) error: AxiosError
}

typescript playground

Registering a global Error

TanStack Query v5 allows for a way to set a global Error type for everything, without having to specify generics on call-sides, by amending the Register interface. This will make sure inference still works, but the error field will be of the specified type:

tsx
import '@tanstack/solid-query'

declare module '@tanstack/solid-query' {
  interface Register {
    defaultError: AxiosError
  }
}

const query = createQuery(() => ({
  queryKey: ['groups'],
  queryFn: fetchGroups,
}))

query.error
//    ^? (property) error: AxiosError | null

import '@tanstack/solid-query'

declare module '@tanstack/solid-query' {
  interface Register {
    defaultError: AxiosError
  }
}

const query = createQuery(() => ({
  queryKey: ['groups'],
  queryFn: fetchGroups,
}))

query.error
//    ^? (property) error: AxiosError | null

Registering global Meta

Similarly to registering a global error type you can also register a global Meta type. This ensures the optional meta field on queries and mutations stays consistent and is type-safe. Note that the registered type must extend Record<string, unknown> so that meta remains an object.

ts
import '@tanstack/solid-query'

interface MyMeta extends Record<string, unknown> {
  // Your meta type definition.
}

declare module '@tanstack/solid-query' {
  interface Register {
    queryMeta: MyMeta
    mutationMeta: MyMeta
  }
}

import '@tanstack/solid-query'

interface MyMeta extends Record<string, unknown> {
  // Your meta type definition.
}

declare module '@tanstack/solid-query' {
  interface Register {
    queryMeta: MyMeta
    mutationMeta: MyMeta
  }
}

Typing Query Options

If you inline query options into createQuery, you'll get automatic type inference. However, you might want to extract the query options into a separate function to share them between createQuery and e.g. prefetchQuery. In that case, you'd lose type inference. To get it back, you can use queryOptions helper:

ts
import { queryOptions } from '@tanstack/solid-query'

function groupOptions() {
  return queryOptions({
    queryKey: ['groups'],
    queryFn: fetchGroups,
    staleTime: 5 * 1000,
  })
}

createQuery(groupOptions)
queryClient.prefetchQuery(groupOptions())

import { queryOptions } from '@tanstack/solid-query'

function groupOptions() {
  return queryOptions({
    queryKey: ['groups'],
    queryFn: fetchGroups,
    staleTime: 5 * 1000,
  })
}

createQuery(groupOptions)
queryClient.prefetchQuery(groupOptions())

Further, the queryKey returned from queryOptions knows about the queryFn associated with it, and we can leverage that type information to make functions like queryClient.getQueryData aware of those types as well:

ts
function groupOptions() {
  return queryOptions({
    queryKey: ['groups'],
    queryFn: fetchGroups,
    staleTime: 5 * 1000,
  })
}

const data = queryClient.getQueryData(groupOptions().queryKey)
//    ^? const data: Group[] | undefined

function groupOptions() {
  return queryOptions({
    queryKey: ['groups'],
    queryFn: fetchGroups,
    staleTime: 5 * 1000,
  })
}

const data = queryClient.getQueryData(groupOptions().queryKey)
//    ^? const data: Group[] | undefined

Without queryOptions, the type of data would be unknown, unless we'd pass a generic to it:

ts
const data = queryClient.getQueryData<Group[]>(['groups'])

const data = queryClient.getQueryData<Group[]>(['groups'])

Typesafe disabling of queries using skipToken

If you are using TypeScript, you can use the skipToken to disable a query. This is useful when you want to disable a query based on a condition, but you still want to keep the query to be type safe.

Read more about it in the Disabling Queries guide.

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