example.spec.js

import { expect } from 'chai'
import { spy } from 'sinon'
import { shallowMount, createLocalVue } from '@vue/test-utils'
import VueRouter from 'vue-router'
import Vuex from 'vuex'
import Sidenav from '@/components/SideNav.vue'

const localVue = createLocalVue()
localVue.use(Vuex)
localVue.use(VueRouter)
const router = new VueRouter()

describe('Sidenav.vue', () => {
  let actions, state, store
  beforeEach(() => {
    state = {
      pages: []
    }
    actions = {
      fetchPages: spy()
    }
    store = new Vuex.Store({
      state,
      actions
    })
  })
  it('calls prefetched pages', () => {
    const wrapper = shallowMount(Sidenav, {
      store,
      localVue,
      router
    })
    console.log(actions)
    expect(actions.fetchPages).should.have.been.called
  })
})