localStorageMiddleware.js

const middleware = () => store => next => action => {
  // Get the state before and after the action was performed
  const previousToken = store.getState().token;
  next(action);
  const nextToken = store.getState().token;

  // Respond to changes
  if (nextToken !== previousToken) localStorage.setItem('token', nextToken);
};


// Get initial state from localStorage
const token = localStorage.getItem('token');
const initialState = token
  ? _.set(defaultState, 'token', token)
  : defaultState;
const middlewares = applyMiddleware(middleware());
const store = createStore(reducers, initialState, middlewares);