index.js

import clone from '@ianwalter/clone'
import { merge } from '@generates/merger'

export default function VuexReset (opts = {}) {
  const { ssr, trigger } = merge({ trigger: 'reset' }, opts)

  return store => {
    // Extract the initial state from the store so that it can be used to reset
    // the store when a trigger mutation is executed.
    const initialState = clone(store.state)

    // If the Vuex store needs to be hydrated from SSR data, add it to the store
    // after the initialState is set so that initialState isn't polluted with
    // SSR data and the store can be reset cleanly.
    if (ssr) {
      store.replaceState(merge(clone(store.state), clone(ssr)))
    }

    store.subscribe((mutation, state) => {
      if (mutation.type === trigger) {
        const newState = clone(initialState)

        // Don't reset route module if set.
        if (state.route) {
          newState.route = clone(state.route)
        }

        // Reset the entire store state.
        store.replaceState(newState)
      } else {
        // Extract the name of the module and mutation.
        let mod = mutation.type.split('/')
        const mut = mod.pop()

        if (mut === trigger) {
          // Reset the state for the module containing the mutation.
          mod = mod.join('/')
          store.replaceState({
            ...clone(state),
            [mod]: clone(initialState[mod])
          })
        }
      }
    })

    store.registerModuleState = (namespace, mod) => {
      store.registerModule(namespace, mod)
      initialState[namespace] = clone(mod.state)
    }

    store.unregisterModuleState = namespace => {
      store.unregisterModule(namespace)
      delete initialState[namespace]
    }
  }
}