From 00c3c8c1c82902a0dd47a28ef53717d9897b8e97 Mon Sep 17 00:00:00 2001
From: Wonsuk Choi <sukvvon@gmail.com>
Date: Tue, 16 Jun 2026 17:37:30 +0900
Subject: [PATCH] test(solid-query/useQuery): add type test for generic
 indexed-access 'TData' regression guard

---
 .../src/__tests__/useQuery.test-d.tsx         | 48 +++++++++++++++++++
 1 file changed, 48 insertions(+)

diff --git a/packages/solid-query/src/__tests__/useQuery.test-d.tsx b/packages/solid-query/src/__tests__/useQuery.test-d.tsx
index 08fb3f17bc..278f4710b8 100644
--- a/packages/solid-query/src/__tests__/useQuery.test-d.tsx
+++ b/packages/solid-query/src/__tests__/useQuery.test-d.tsx
@@ -250,4 +250,52 @@ describe('useQuery', () => {
       })
     })
   })
+
+  describe('generic indexed access TData', () => {
+    // https://github.com/TanStack/query/issues/9937
+    it('should be assignable back to its source indexed type when passed to a generic function parameter', () => {
+      enum DataType {
+        Account = 'account',
+        Product = 'product',
+      }
+
+      interface Account {
+        name: string
+      }
+      interface Product {
+        code: string
+      }
+
+      type DataTypeToEntity = {
+        [DataType.Account]: Account
+        [DataType.Product]: Product
+      }
+
+      const getData = <TDataType extends DataType>(
+        _dataType: TDataType,
+      ): Promise<DataTypeToEntity[TDataType]> =>
+        Promise.resolve({} as DataTypeToEntity[TDataType])
+
+      const getLabel = <TDataType extends DataType>(
+        _dataType: TDataType,
+        _data: DataTypeToEntity[TDataType],
+      ) => 'test'
+
+      function Test<TDataType extends DataType>(props: {
+        dataType: TDataType
+      }) {
+        const { data } = useQuery(() => ({
+          queryKey: ['test'],
+          queryFn: () => getData(props.dataType),
+        }))
+
+        // Regression guard: this call must compile. With the previous
+        // hand-rolled NoInfer, `data` failed to flow back into the generic
+        // indexed-access parameter `DataTypeToEntity[TDataType]`.
+        return data ? getLabel(props.dataType, data) : null
+      }
+
+      expectTypeOf(Test).toBeFunction()
+    })
+  })
 })