"store" is read-only React testing library

Question

I'm beginner on react testing, here the createTestStore uses the built in redux functions createStore and combineReducers with references to my actual reducer (how this should be done using toolkits configureStore?). reducer should automatically get initialized with the correct initial state. but i'm getting this: "store" is read-only. and its pointing to store which is in beforeEach. English is not my mother language so could be mistakes, any suggestions?

in my store.ts:

 // this is for testing export function createTestStore() { const store = createStore( combineReducers({ user: userReducer, config: configReducer, }) ); return store; } export const history: History = createBrowserHistory(); const rootReducer = (history: any) => ({ router: connectRouter(history), app: appReducer, user: userReducer, config: configReducer, }); const preloadedState = {}; export const store = configureStore({ middleware: [thunk as ThunkMiddleware, routerMiddleware(history)], reducer: rootReducer(history) as any, preloadedState, }); export type AppDispatch = typeof store.dispatch; export const useAppDispatch = () => useDispatch<AppDispatch>(); //

my test:

 let store; describe("a test", () => { beforeEach(() => { store = createTestStore(); }); test('Component with a full reducer flow', async () => { // Create a redux store const { findByText } = render( <Provider store={store}> <ComponentToTest /> </Provider> ); await findByText('This text is now visible because your state was updated by the reducer'); }); });