api.js

export let axiosInstance = axios.create({
  headers: { 'bearer': jwtToken }
})

export const updateInstance = newToken => {
  const settings = {
    ...(newToken & { headers: { 'bearer': newToken } }),
    baseUrl: 'google.com'
  }
  
  axiosInstance = axios.create(settings)
}

export const sendGetRequest = url => axiosInstance.get(url)

authentication.js

import { updateInstance } from '/api-layer'
import { FETCH_USER_ERROR } from '/user';
import { FETCH_VIDEOS_ERROR } from '/videos' 

const initState = {
  jwtToken: null
}

export const updateToken = newToken => {
  updateInstance(newToken);

  return {
    type: UPDATE_TOKEN,
    payload: { jwtToken: newToken }
  }
}

export const resetToken = () => {
  updateInstance(null);

  return { type: RESET_TOKEN }
}

const authentication = (action, state = initState) => {
  switch(actiion.type) {
    case FETCH_USER_ERROR:
    case FETCH_VIDEOS_ERROR:
      return action.payload.error.statusCode === 401 ? { ...state, jwtToken: null } : state
  }
}

component.js

import { fetchUsers } from './redux/users'

const mapStateToProps = state => {
  isAuthenticated: Boolean(state.authentication.jwtToken)
}

const mapDispatchToProps = { fetchUsers }

class SomeComponent extends React.Component {
  componentDidMount() {
    const { isAuthenticated, fetchUsers } = this.props;

    if (isAuthenticated) {
      fetchUsers()
    }
  }
  
  render() {
    const { isAuthenticated, fetchUsers } = this.props;

    return isAuthenticated ? <div class='content'/> : <div class='access-denied' />
  }
}
  
export default connect(mapStateToProps, mapDispatchToProps)(SomeComponent)

users.js

import { get } from './api-layer';
import { resetToken } from './authentication'

export const FETCH_USER_ERROR = 'FETCH_USER_ERROR'

export const fetchUsers = () => async dispatch => {
  dispatch(fetchingUsers());

  try {
    const { data } = await get('/users');

    dispatch(fetchingUsersSuccess(data.items))
  } catch(e) {
    dispatch(fetchingUsersError(e))
  }
}