javascript - router.push无效

import Vue from 'vue'
import App from './App'
import VueRouter from './router'

Vue.config.productionTip = false

VueRouter.push('/goods')

/ eslint-disable no-new /
new Vue({
el: '#app',
router: VueRouter,
template: '<App/>',
components: { App }
})

在这里VueRouter.push('/goods')是有效的

import Vue from 'vue'
import Router from 'vue-router'
import goods from '../components/goods/goods'
import seller from '../components/seller/seller'
import ratings from '../components/ratings/ratings'

Vue.use(Router)

/ eslint-disable no-new /
const routes = [
{ path: '/seller', component: seller },
{ path: '/ratings', component: ratings },
{ path: '/goods', component: goods }
]

Router.push('/goods')

export default new Router({
routes
})

在这里的.push无效
不是很明白这里的问题