const router = new VueRouter({ ... })

router.beforeEach((to, from, next) => {
 // ...
})

const router = new VueRouter({
 base: __dirname,
 routes
});

new Vue({ // eslint-disable-line
 el: '#app',
 render: h => h(App),
 router
});

let indexScrollTop = 0;
router.beforeEach((route, redirect, next) => {
 if (route.path !== '/') {
  indexScrollTop = document.body.scrollTop;
 }
 document.title = route.meta.title || document.title;
 next();
});

router.afterEach(route => {
 if (route.path !== '/') {
  document.body.scrollTop = 0;
 } else {
  Vue.nextTick(() => {
   document.body.scrollTop = indexScrollTop;
  });
 }
})