问Vue mapState对象正在改变vuex状态

EN

export default function() {
  return {
    profile: {
      avatar: null,
      name: 'Thomas Smith',
      contact: 'thomas.smith@bootiq.io',
      branch: 'BIQ-PRAGUE',
      position: 'Software Developer / UI Designer',
      projects: [
        {
          company: 'Company',
          project: 'E-Shop Platform',
          role: 'Frontend Developer, Consultant'
        },
        {
          company: 'BIQ-INTERNAL',
          project: 'Skillboard',
          role: 'UI Design, Project Lead'
        }
      ],
      interests: ['Frontend Applications', 'UI Design', 'Stalking random people'],
      skills: [
        {
          name: 'Javascript',
          level: 2
        },
        {
          name: 'Vue',
          level: 3
        },
        {
          name: 'Angular',
          level: 1
        }
      ]
    }
  }
}

computed: {
    ...mapState({
      stateSkillList: state => state.skill.skillList
    }),

    ...mapGetters({
      user: 'user/getUser'
    })
  },

  mounted() {
    if (this.user) {
      this.data = Object.assign({}, this.data, this.user)

      if (this.data.projects.length === 0) {
        this.data.projects = [this.baseItems.projects]
      }

      if (this.data.skills.length) {
        this.filterSkillList()
      }
    }
  },

vue.esm.js?a026:628 [Vue warn]: Error in callback for watcher "function () { return this._data.$$state }": "Error: [vuex] do not mutate vuex store state outside mutation handlers."

(found in <Root>)
warn @ vue.esm.js?a026:628
logError @ vue.esm.js?a026:1893
globalHandleError @ vue.esm.js?a026:1888
handleError @ vue.esm.js?a026:1848
run @ vue.esm.js?a026:4579
update @ vue.esm.js?a026:4551
notify @ vue.esm.js?a026:739
mutator @ vue.esm.js?a026:891
handleRemoveSkill @ EditProfile.vue?05c4:306
click @ EditProfile.vue?0ae8:411
invokeWithErrorHandling @ vue.esm.js?a026:1863
invoker @ vue.esm.js?a026:2188
original._wrapper @ vue.esm.js?a026:7565
vue.esm.js?a026:1897 Error: [vuex] do not mutate vuex store state outside mutation handlers.
    at assert (vuex.esm.js?2f62:90)
    at Vue.store._vm.$watch.deep (vuex.esm.js?2f62:814)
    at Watcher.run (vue.esm.js?a026:4577)
    at Watcher.update (vue.esm.js?a026:4551)
    at Dep.notify (vue.esm.js?a026:739)
    at Array.mutator (vue.esm.js?a026:891)
    at VueComponent.handleRemoveSkill (EditProfile.vue?05c4:306)
    at click (eval at ./node_modules/cache-loader/dist/cjs.js?{"cacheDirectory":"node_modules/.cache/vue-loader","cacheIdentifier":"6bb1df4e-vue-loader-template"}!./node_modules/vue-loader/lib/loaders/templateLoader.js?!./node_modules/vuetify-loader/lib/loader.js?!./node_modules/cache-loader/dist/cjs.js?!./node_modules/vue-loader/lib/index.js?!./src/views/EditProfile.vue?vue&type=template&id=7b259475&scoped=true& (app.js:1178), <anonymous>:414:44)
    at invokeWithErrorHandling (vue.esm.js?a026:1863)
    at HTMLButtonElement.invoker (vue.esm.js?a026:2188)

handleAddSkill(name) {
  this.data.skills.push({ name })
  this.dataSkillFilteredList = this.dataSkillFilteredList.filter(item => item !== name)
  this.dataSkillList = this.dataSkillFilteredList
},