mutationaction.ts

import {Module, VuexModule, MutationAction} from 'vuex-module-decorators'
import {ConferencesEntity, EventsEntity} from '@/models/definitions' 

@Module
export default class HGAPIModule extends VuexModule {
  conferences: Array<ConferencesEntity> = []
  events: Array<EventsEntity> = []

  // 'events' and 'conferences' are replaced by returned object
  // whose shape must be `{events: {...}, conferences: {...} }`
  @MutationAction({mutate: ['events', 'conferences']})
  async fetchAll () {
    const response: Response = await getJSON('https://hasgeek.github.io/events/api/events.json')
    return response
  }
}