fix(angular-query-experimental): allow returning undefined in initial…

…Data function

Fix incorrect types that disallowed that. This is necessary because the initialData function can typically read cache synchronously and need to be able to signal to the query if there is a cache miss and an actual fetch needs to be deployed.

No breaking changes, any code that worked before should work now as well.

packages/angular-query-experimental/src/__tests__/query-options.test-d.ts

@@ -25,6 +25,25 @@ describe('queryOptions', () => {
       },
     })
   })
+
+  test('should allow undefined response in initialData', () => {
+    return (id: string | null) =>
+      queryOptions({
+        queryKey: ['todo', id],
+        queryFn: () =>
+          Promise.resolve({
+            id: '1',
+            title: 'Do Laundry',
+          }),
+        initialData: () =>
+          !id
+            ? undefined
+            : {
+                id,
+                title: 'Initial Data',
+              },
+      })
+  })
 })
 
 test('should work when passed to injectQuery', () => {

packages/angular-query-experimental/src/query-options.ts

@@ -1,4 +1,9 @@
-import type { DataTag, DefaultError, QueryKey } from '@tanstack/query-core'
+import {
+  DataTag,
+  DefaultError,
+  QueryKey,
+  InitialDataFunction,
+} from '@tanstack/query-core'
 import type { CreateQueryOptions } from './types'
 
 export type UndefinedInitialDataOptions<
@@ -20,7 +25,7 @@ export type DefinedInitialDataOptions<
 > = CreateQueryOptions<TQueryFnData, TError, TData, TQueryKey> & {
   initialData:
     | NonUndefinedGuard<TQueryFnData>
-    | (() => NonUndefinedGuard<TQueryFnData>)
+    | InitialDataFunction<NonUndefinedGuard<TQueryFnData>>
 }
 
 export function queryOptions<