Project/projectreact/src/reducers/index.js

import thunk  from 'redux-thunk'
import {createStore, combineReducers,applyMiddleware } from 'redux';
import { actionFindUser , actionSnippetFindByOwner} from '../actions';


function promiseReducer(state , {type, name ,status , payload, error}) {
  if (!state){
      return {} //{status , payload , error}
  }
  if (type === 'PROMISE') {
      return {
          ...state,
          [name]: {status,payload , error}
      }
  }
  return state
}

function authReducer(state, action){ //....
    if (state === undefined){
        if (!localStorage.authToken){
            return {}
        }
        action.token = localStorage.authToken
        action.type = 'LOGIN'
        // добавить в action token из localStorage, и проимитировать LOGIN 
    }
    if (action.type === 'LOGIN'){
        localStorage.authToken = action.token
        function jwt_decode (token) {
            var start64Url = token.split('.')[1]
            return JSON.parse(atob(start64Url))
        }
        return {token: action.token, payload: jwt_decode(action.token)}
    }
    if (action.type === 'LOGOUT'){
        localStorage.removeItem("authToken")
        //вернуть пустой объект
        return {}
    }
    return state
}
export const reducers = {
    promise:promiseReducer,
    auth:authReducer
}

export const store = createStore(combineReducers(reducers), applyMiddleware(thunk))
const unsubscribe = store.subscribe(() => console.log('result here',store.getState()))
if (localStorage.authToken) {
    store.dispatch(actionFindUser())
    store.dispatch(actionSnippetFindByOwner(store.getState().auth.payload.sub.id))
}

export default store