configureStore.js

import { createStore, applyMiddleware } from 'redux'
import reducer from './reducers'

export default function configureStore (initialState) {
  const logger = require('redux-logger')({
    level: 'info',
    collapsed: false
  })
  let store

  if (process.env.NODE_ENV === 'development') {
    const createStoreWithMiddleware = applyMiddleware(
      logger
    )(createStore)
    store = createStoreWithMiddleware(reducer, initialState)
  } else {
    store = createStore(reducer, initialState)
  }

  if (module.hot) {
    // Enable Webpack hot module replacement for reducers
    module.hot.accept('./reducers', () => {
      const nextReducer = require('./reducers').default
      store.replaceReducer(nextReducer)
    })
  }

  return store
}