fix(nuxt): add overloads for asyncData generic + default (#22258)

packages/nuxt/src/app/composables/asyncData.ts

@@ -78,6 +78,16 @@ export function useAsyncData<
   handler: (ctx?: NuxtApp) => Promise<ResT>,
   options?: AsyncDataOptions<ResT, DataT, PickKeys, DefaultT>
 ): AsyncData<PickFrom<DataT, PickKeys> | DefaultT, DataE | null>
+export function useAsyncData<
+  ResT,
+  DataE = Error,
+  DataT = ResT,
+  PickKeys extends KeysOf<DataT> = KeysOf<DataT>,
+  DefaultT = DataT,
+> (
+  handler: (ctx?: NuxtApp) => Promise<ResT>,
+  options?: AsyncDataOptions<ResT, DataT, PickKeys, DefaultT>
+): AsyncData<PickFrom<DataT, PickKeys> | DefaultT, DataE | null>
 export function useAsyncData<
   ResT,
   DataE = Error,
@@ -89,6 +99,17 @@ export function useAsyncData<
   handler: (ctx?: NuxtApp) => Promise<ResT>,
   options?: AsyncDataOptions<ResT, DataT, PickKeys, DefaultT>
 ): AsyncData<PickFrom<DataT, PickKeys> | DefaultT, DataE | null>
+export function useAsyncData<
+  ResT,
+  DataE = Error,
+  DataT = ResT,
+  PickKeys extends KeysOf<DataT> = KeysOf<DataT>,
+  DefaultT = DataT,
+> (
+  key: string,
+  handler: (ctx?: NuxtApp) => Promise<ResT>,
+  options?: AsyncDataOptions<ResT, DataT, PickKeys, DefaultT>
+): AsyncData<PickFrom<DataT, PickKeys> | DefaultT, DataE | null>
 export function useAsyncData<
   ResT,
   DataE = Error,
@@ -267,6 +288,16 @@ export function useLazyAsyncData<
   handler: (ctx?: NuxtApp) => Promise<ResT>,
   options?: Omit<AsyncDataOptions<ResT, DataT, PickKeys, DefaultT>, 'lazy'>
 ): AsyncData<PickFrom<DataT, PickKeys> | DefaultT, DataE | null>
+export function useLazyAsyncData<
+  ResT,
+  DataE = Error,
+  DataT = ResT,
+  PickKeys extends KeysOf<DataT> = KeysOf<DataT>,
+  DefaultT = DataT,
+> (
+  handler: (ctx?: NuxtApp) => Promise<ResT>,
+  options?: Omit<AsyncDataOptions<ResT, DataT, PickKeys, DefaultT>, 'lazy'>
+): AsyncData<PickFrom<DataT, PickKeys> | DefaultT, DataE | null>
 export function useLazyAsyncData<
   ResT,
   DataE = Error,
@@ -278,6 +309,18 @@ export function useLazyAsyncData<
   handler: (ctx?: NuxtApp) => Promise<ResT>,
   options?: Omit<AsyncDataOptions<ResT, DataT, PickKeys, DefaultT>, 'lazy'>
 ): AsyncData<PickFrom<DataT, PickKeys> | DefaultT, DataE | null>
+export function useLazyAsyncData<
+  ResT,
+  DataE = Error,
+  DataT = ResT,
+  PickKeys extends KeysOf<DataT> = KeysOf<DataT>,
+  DefaultT = DataT,
+> (
+  key: string,
+  handler: (ctx?: NuxtApp) => Promise<ResT>,
+  options?: Omit<AsyncDataOptions<ResT, DataT, PickKeys, DefaultT>, 'lazy'>
+): AsyncData<PickFrom<DataT, PickKeys> | DefaultT, DataE | null>
+
 export function useLazyAsyncData<
   ResT,
   DataE = Error,

packages/nuxt/src/app/composables/fetch.ts

@@ -41,6 +41,19 @@ export function useFetch<
   request: Ref<ReqT> | ReqT | (() => ReqT),
   opts?: UseFetchOptions<_ResT, DataT, PickKeys, DefaultT, ReqT, Method>
 ): AsyncData<PickFrom<DataT, PickKeys> | DefaultT, ErrorT | null>
+export function useFetch<
+  ResT = void,
+  ErrorT = FetchError,
+  ReqT extends NitroFetchRequest = NitroFetchRequest,
+  Method extends AvailableRouterMethod<ReqT> = ResT extends void ? 'get' extends AvailableRouterMethod<ReqT> ? 'get' : AvailableRouterMethod<ReqT> : AvailableRouterMethod<ReqT>,
+  _ResT = ResT extends void ? FetchResult<ReqT, Method> : ResT,
+  DataT = _ResT,
+  PickKeys extends KeysOf<DataT> = KeysOf<DataT>,
+  DefaultT = DataT,
+> (
+  request: Ref<ReqT> | ReqT | (() => ReqT),
+  opts?: UseFetchOptions<_ResT, DataT, PickKeys, DefaultT, ReqT, Method>
+): AsyncData<PickFrom<DataT, PickKeys> | DefaultT, ErrorT | null>
 export function useFetch<
   ResT = void,
   ErrorT = FetchError,
@@ -136,6 +149,19 @@ export function useLazyFetch<
   request: Ref<ReqT> | ReqT | (() => ReqT),
   opts?: Omit<UseFetchOptions<_ResT, DataT, PickKeys, DefaultT, ReqT, Method>, 'lazy'>
 ): AsyncData<PickFrom<DataT, PickKeys> | DefaultT, ErrorT | null>
+export function useLazyFetch<
+  ResT = void,
+  ErrorT = FetchError,
+  ReqT extends NitroFetchRequest = NitroFetchRequest,
+  Method extends AvailableRouterMethod<ReqT> = ResT extends void ? 'get' extends AvailableRouterMethod<ReqT> ? 'get' : AvailableRouterMethod<ReqT> : AvailableRouterMethod<ReqT>,
+  _ResT = ResT extends void ? FetchResult<ReqT, Method> : ResT,
+  DataT = _ResT,
+  PickKeys extends KeysOf<DataT> = KeysOf<DataT>,
+  DefaultT = DataT,
+> (
+  request: Ref<ReqT> | ReqT | (() => ReqT),
+  opts?: Omit<UseFetchOptions<_ResT, DataT, PickKeys, DefaultT, ReqT, Method>, 'lazy'>
+): AsyncData<PickFrom<DataT, PickKeys> | DefaultT, ErrorT | null>
 export function useLazyFetch<
   ResT = void,
   ErrorT = FetchError,

test/fixtures/basic-types/types.ts

@@ -309,6 +309,33 @@ describe('composables', () => {
     expectTypeOf(useFetch('/test', { default: () => 500 }).data).toEqualTypeOf<Ref<unknown>>()
   })
 
+  it('correct types when using ResT type-assertion with default function', () => {
+    // @ts-expect-error default type should match generic type
+    useFetch<string>('/test', { default: () => 0 })
+    // @ts-expect-error default type should match generic type
+    useLazyFetch<string>('/test', { default: () => 0 })
+    // @ts-expect-error default type should match generic type
+    useAsyncData<string>(() => $fetch('/test'), { default: () => 0 })
+    // @ts-expect-error default type should match generic type
+    useLazyAsyncData<string>(() => $fetch('/test'), { default: () => 0 })
+
+    expectTypeOf(useFetch<string>('/test', { default: () => 'test' }).data).toEqualTypeOf<Ref<string>>()
+    expectTypeOf(useLazyFetch<string>('/test', { default: () => 'test' }).data).toEqualTypeOf<Ref<string>>()
+    expectTypeOf(useAsyncData<string>(() => $fetch('/test'), { default: () => 'test' }).data).toEqualTypeOf<Ref<string>>()
+    expectTypeOf(useLazyAsyncData<string>(() => $fetch('/test'), { default: () => 'test' }).data).toEqualTypeOf<Ref<string>>()
+
+    // transform must match the explicit generic because of typescript limiations microsoft/TypeScript#14400
+    expectTypeOf(useFetch<string>('/test', { transform: () => 'transformed' }).data).toEqualTypeOf<Ref<string | null>>()
+    expectTypeOf(useLazyFetch<string>('/test', { transform: () => 'transformed' }).data).toEqualTypeOf<Ref<string | null>>()
+    expectTypeOf(useAsyncData<string>(() => $fetch('/test'), { transform: () => 'transformed' }).data).toEqualTypeOf<Ref<string | null>>()
+    expectTypeOf(useLazyAsyncData<string>(() => $fetch('/test'), { transform: () => 'transformed' }).data).toEqualTypeOf<Ref<string | null>>()
+
+    expectTypeOf(useFetch<string>('/test', { default: () => 'test', transform: () => 'transformed' }).data).toEqualTypeOf<Ref<string>>()
+    expectTypeOf(useLazyFetch<string>('/test', { default: () => 'test', transform: () => 'transformed' }).data).toEqualTypeOf<Ref<string>>()
+    expectTypeOf(useAsyncData<string>(() => $fetch('/test'), { default: () => 'test', transform: () => 'transformed' }).data).toEqualTypeOf<Ref<string>>()
+    expectTypeOf(useLazyAsyncData<string>(() => $fetch('/test'), { default: () => 'test', transform: () => 'transformed' }).data).toEqualTypeOf<Ref<string>>()
+  })
+
   it('infer request url string literal from server/api routes', () => {
     // request can accept dynamic string type
     const dynamicStringUrl = 'https://example.com/api'