Correct TypeScript typing example for Redux Thunk actions

redux-actions.ts

import {Action, ActionCreator, Dispatch} from 'redux';
import {ThunkAction} from 'redux-thunk';

// Redux action
const reduxAction: ActionCreator<Action> = (text: string) => {
  return {
    type: SET_TEXT,
    text
  };
};

// Redux-Thunk action
const thunkAction: ActionCreator<ThunkAction<Action, IState, void>> = (
  text: string
) => {
  return (dispatch: Dispatch<IState>): Action => {
    return dispatch({
      type: SET_TEXT,
      text
    });
  };
};

// Async Redux-Thunk action
const asyncThinkAction: ActionCreator<
  ThunkAction<Promise<Action>, IState, void>
> = () => {
  return async (dispatch: Dispatch<IState>): Promise<Action> => {
    try {
      const text = await Api.call();
      return dispatch({
        type: SET_TEXT,
        text
      });
    } catch (e) {}
  };
};

I am migrating to Typescript for fun, but I am not understanding how I can avoid all the boilerplate when I am writing my actions and reducers like this:

localUserReducer.js

const initialState = {
  fetching: false,
  fetched: false,
  user: undefined,
  errors: undefined,
};

export default function (state = initialState, action) {
  switch (action.type) {
    case 'GET_USER_PENDING':
      return {
        ...state,
        fetching: true,
      };
    case 'GET_USER_FULFILLED':
      return {
        ...state,
        fetching: false,
        fetched: true,
        user: action.payload,
      };
    case 'GET_USER_REJECTED':
      return {
        ...state,
        fetching: false,
        errors: action.payload,
      };
    default:
      return state;
  }
}

localUserActions.js

import axios from 'axios';

export const getUser = () => async (dispatch) => {
  dispatch({ type: 'GET_USER_PENDING' });
  try {
    const { data } = await axios.get('/api/auth/local/current');
    dispatch({ type: 'GET_USER_FULFILLED', payload: data });
  } catch (err) {
    dispatch({ type: 'GET_USER_REJECTED', payload: err.response.data });
  }
};

Would I be expected to write an interface for each _PENDING, _FULFILLED, and _REJECTED action?

I may have a huge misunderstand of redux-thunk as I am a newbie. I don't understand how I can send _REJECTED actions if I use the implementation of Typescript and redux-thunk documented here: https://redux.js.org/recipes/usage-with-typescript#usage-with-redux-thunk

export type ThunkResult<R> = ThunkAction<R, IStoreState, null, IStoreActions>

Just want to say thank you, I struggled with it and your answer helped me solve the problem. 😄

Thanks @milankorsos!

Please hellp me )))

export type ThunkResult2<R> = ThunkAction<R, AppStateType, null, Action>
export type ThunkDispatch2 = ThunkDispatch<AppStateType, null, Action>

export const login = (auth: any): ThunkResult2<Promise<{a: boolean, b: string}>> => async (dispatch: ThunkDispatch2) => {
    const res =  await AuthApi.authentication(auth);
    const r = dispatch(AuthActions.login(new Auth({ ...res })));
    return {
        a: true,
        b: '123'
    } // this very well work
}

// but
......

            onSubmit={ async (values) => {
                const res = await dispatch(login(values))
                console.log(res.a) // this problem
            }}

TS2339: Property 'a' does not exist on type 'ThunkAction { a: boolean; b: string; }>, CombinedState{ auth: never; }>, null, Action >'

I still can't locate IStoreState

Maybe this is right place to use "any" when i must make type for thunk action in my props.