fix(core): correct useCustom return type to reflect empty object during loading

.changeset/fix-useCustom-return-type.md

@@ -0,0 +1,11 @@
+---
+"@refinedev/core": patch
+---
+
+fix(core): correct useCustom return type to reflect empty object during loading
+
+The `useCustom` hook returns an empty object for `result.data` while loading, but the TypeScript type only indicated it would be `CustomResponse<TData>["data"]`. This caused the type system to not catch potential runtime errors when accessing properties on `result.data` during the loading state.
+
+Updated the return type to `CustomResponse<TData>["data"] | Record<string, never>` to accurately represent that `result.data` can be an empty object while loading.
+
+[Resolves #7088](https://github.com/refinedev/refine/issues/7088)

packages/core/src/hooks/data/useCustom.ts

@@ -110,7 +110,7 @@ export type UseCustomProps<TQueryFnData, TError, TQuery, TPayload, TData> = {
 export type UseCustomReturnType<TData, TError> = {
   query: QueryObserverResult<CustomResponse<TData>, TError>;
   result: {
-    data: CustomResponse<TData>["data"];
+    data: CustomResponse<TData>["data"] | Record<string, never>;
   };
 } & UseLoadingOvertimeReturnType;