project/src/reducers/auth.js

import { decode as atob } from 'base-64'

// функция authReducer

let signatureToken = (token) => JSON.parse(atob(token.split(".")[1]))

function authReducer(state, { type, token }) {

    if (state === undefined) {
        if (localStorage.authToken) {
            type = "LOGIN"
            token = localStorage.authToken
        } else {
            return {}
        }
    }

    if (type === "LOGIN") {
        console.log('LOGIN')
        localStorage.authToken = token
        return {token, payload: signatureToken(token)}
    }

    if (type === "LOGOUT") {
        console.log('LOGOUT')
        localStorage.removeItem("authToken")
        return {}
    }

    return state
}

export default authReducer;