router - refactor

// redux utilities
// create a store, apply middlewares to it
import { createStore, applyMiddleware } from 'redux';
// middleware to parse actions' promises
import { promiseMiddleware } from './middleware';

// defaultstate + trivial reducer
const defaultState = {
  appName: 'conduit',
  articles: null,
};
const reducer = function(state = defaultState, action) {
  // update state based on the action type
  switch (action.type) {
    // HOME_PAGE_LOADED => put articles into state
    case 'HOME_PAGE_LOADED':
      return { ...state, articles: action.payload.articles };
    // unrecognized action type => don't change state
    default:
      return state;
  }
};

const middleware = applyMiddleware(promiseMiddleware);

// create store
const store = createStore(reducer, middleware);

export default store;