Redux Toolkit: How to refer action created with createAction as type

Question

Redux toolkit provides createAction helper method. I am having trouble referring actions created with createAction as type.

For example:

const getData = createAction<PayloadAction<number>>('user/getData')

function* exampleSaga(action: ?) {
   ...
}

How can I tell exampleSaga that action is of type getData?

---

To see how I've tried doing it, refer the below (example) code and see comments for the problem I am facing:

reducer.ts

import { createAction, PayloadAction } from '@reduxjs/toolkit';

export const getData = createAction<PayloadAction<number>>('user/getData');

const userSlice = createSlice({
  name: userSliceName,
  initialState,
  reducers: {
    getUser(state: IUserState): void {
      state.loading = true;
      state.error = null;
    },
    getUserSuccess(state: IUserState, action: PayloadAction<{ user: IUser }>): void {
      const { user } = action.payload;
      state.user = user;
      state.loading = false;
      state.error = null;
    },
    getUserFailure(state: IUserState, action: PayloadAction<string>): void {
      state.loading = false;
      state.error = action.payload;
    },
  },
});

export type UserSaga = Generator<
  | CallEffect<IUser>
  | PutEffect<typeof getUserSuccess>
  | PutEffect<typeof getUserFailure>
  | ForkEffect<never>
>;

sagas.ts

import { UserSaga, getData } from './reducer.ts';

// For the following fetchUser saga arguments, how can I define that 'action' is of type getData, imported from the above 'reducer.ts' file.
function* fetchUser(action: PayloadAction<typeof getData>): UserSaga {
  try {
    const userId = action.payload;
    // Problem is here
    // I expect userId to be of type number, whereas it is:
    // ActionCreatorWithPayload<{payload: number, type: string}>
    ...
  } catch (e) {
    ...
  }
}

function* userSaga(): UserSaga {
  const pattern: any = getData.type;
  yield takeLatest(pattern, fetchUser);
}

Answer 1

This is how you will get it using return type of your getData.

function* exampleSaga(action: ReturnType<typeof getData>) {

...

}