# Hot Reloading

Vuex supports hot-reloading mutations, modules, actions and getters during development, using webpack's Hot Module Replacement API(opens new window) . You can also use it in Browserify with the browserify-hmr(opens new window) plugin.

For mutations and modules, you need to use the store.hotUpdate() API method:

// store.js
import Vue from 'vue'
import Vuex from 'vuex'
import mutations from './mutations'
import moduleA from './modules/a'

Vue.use(Vuex)

const state = { ... }

const store = new Vuex.Store({
  state,
  mutations,
  modules: {
    a: moduleA
  }
})

if (module.hot) {
  // accept actions and mutations as hot modules
  module.hot.accept(['./mutations', './modules/a'], () => {
    // require the updated modules
    // have to add .default here due to babel 6 module output
    const newMutations = require('./mutations').default
    const newModuleA = require('./modules/a').default
    // swap in the new modules and mutations
    store.hotUpdate({
      mutations: newMutations,
      modules: {
        a: newModuleA
      }
    })
  })
}

Checkout the counter-hot example(opens new window) to play with hot-reload.

# Dynamic module hot reloading

If you use modules exclusively, you can use require.context to load and hot reload all modules dynamically.

// store.js
import Vue from 'vue'
import Vuex from 'vuex'

// Load all modules.
function loadModules() {
  const context = require.context("./modules", false, /([a-z_]+)\.js$/i)

  const modules = context
    .keys()
    .map((key) => ({ key, name: key.match(/([a-z_]+)\.js$/i)[1] }))
    .reduce(
      (modules, { key, name }) => ({
        ...modules,
        [name]: context(key).default
      }),
      {}
    )

  return { context, modules }
}

const { context, modules } = loadModules()

Vue.use(Vuex)

const store = new Vuex.Store({
  modules
})

if (module.hot) {
  // Hot reload whenever any module changes.
  module.hot.accept(context.id, () => {
    const { modules } = loadModules()

    store.hotUpdate({
      modules
    })
  })
}