test(query-core): add test case for setQueryData type inference in functions

Author: custardcream98

packages/query-core/src/__tests__/queryClient.test-d.tsx

@@ -113,6 +113,19 @@ describe('setQueryData', () => {
 
     expectTypeOf(data).toEqualTypeOf<string | undefined>()
   })
+
+  it('should preserve updater parameter type inference when used in functions with explicit return types', () => {
+    const queryKey = ['key'] as DataTag<Array<string>, number>
+    const queryClient = new QueryClient()
+
+    // Simulate usage inside a function with explicit return type
+    // The outer function returns 'unknown' but this shouldn't affect the updater's type inference
+    ;(() =>
+      queryClient.setQueryData(queryKey, (data) => {
+        expectTypeOf(data).toEqualTypeOf<number | undefined>()
+        return data
+      })) satisfies () => unknown
+  })
 })
 
 describe('getQueryState', () => {
@@ -590,3 +603,28 @@ describe('resetQueries', () => {
     })
   })
 })
+type SuccessCallback = () => unknown
+it('should infer types correctly with expression body arrow functions', () => {
+  const queryKey = ['key'] as DataTag<Array<string>, number>
+  const queryClient = new QueryClient()
+
+  // @ts-expect-error
+  const callbackTest: SuccessCallback = () =>
+    queryClient.setQueryData(queryKey, (data) => {
+      expectTypeOf(data).toEqualTypeOf<number | undefined>()
+      return data
+    })
+})
+
+it('should infer types correctly with block body arrow functions', () => {
+  const queryKey = ['key'] as DataTag<Array<string>, number>
+  const queryClient = new QueryClient()
+
+  // @ts-expect-error
+  const callbackTest2: SuccessCallback = () => {
+    queryClient.setQueryData(queryKey, (data) => {
+      expectTypeOf(data).toEqualTypeOf<number | undefined>()
+      return data
+    })
+  }
+})