createSlice cannot be used in lib.

[jie-huang]

I tried to create a lib which contains simple Slice. If I include the file in the app project directly, it works.
But, if I build a lib which includes the file and add dependency of it, the app reports error

Type 'typeof import("/Users/user/temp/redux-toolkit-app/node_modules/my-redux-lib/dist/types")' is not assignable to type 'Reducer<unknown, AnyAction>'.
  Type 'typeof import("/Users/user/temp/redux-toolkit-app/node_modules/my-redux-lib/dist/types")' provides no match for the signature '(state: unknown, action: AnyAction): unknown'.ts(2322)

Main codes,

// store.ts
import counterReducer from '../features/counter/counterSlice';
import libCounterReducer from 'my-redux-lib';

export const store = configureStore({
  reducer: {
    counter: counterReducer,
    libcounter: libCounterReducer, // error here
  },
});

// counterSlice
export interface CounterState {
  value: number;
}

const initialState: CounterState = {
  value: 0,
};

export const counterSlice = createSlice({
  name: 'counter',
  initialState,
  reducers: {
    increment: (state) => {
      state.value += 1;
    },
  },
});

export const { increment } = counterSlice.actions;

export const selectCount = (state: RootState) => state.counter.value;

export default counterSlice.reducer;

// libCountSlice
export interface LibCounterState {
  value: number;
}

const initialState: LibCounterState = {
  value: 0,
};

export interface Store {
  libcounter: unknown | LibCounterState
}

export const libCounterSlice = createSlice({
  name: 'libcounter',
  initialState,
  reducers: {
    increment: (state) => {
      state.value += 1;
    },
  },
});

export const { increment } = libCounterSlice.actions;

export const selectCount = (state: Store) => (state.libcounter as LibCounterState).value;

export default libCounterSlice.reducer;

[markerikson]

Can you post an actual repo that shows this happening? I know I've seen people use createSlice in a library before. My first guess would be possibly something to do with the build configuration for your library.

[jie-huang]

https://github.com/jie-huang/my-redux-lib
https://github.com/jie-huang/my-redux-app

If you can find an example on how to use createSlice in a lib, please share the link. Thanks

[markerikson]

Unfortunately this isn't something we have time to look into right now. If you have an example that shows it's a bug with RTK itself we can maybe look at it again, but otherwise I would assume this is a problem with your build setup.