新版的vue-cli脚手架中少了dev-server.js文件，怎么模拟后台数据呢？

第一步：，在webpack.dev.conf.js中加入

在webpack.dev.conf.js中引入node中的express框架即后台模拟数据json文件，代码如下：
//这里是模拟后台数据
const express = require('express')
const app = express()
var appData = require('../data.json')
var seller = appData.seller
var goods = appData.goods
var ratings = appData.ratings
var apiRoutes = express.Router()
app.use('/api', apiRoutes)
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作者：jackie_bobo 
来源：CSDN 
原文：https://blog.csdn.net/jackie_bobo/article/details/80654036 
版权声明：本文为博主原创文章，转载请附上博文链接！

第二步：

找到devServe对象

加入下面的，如果报错记得加   ,    号

//找到devServer,添加
before(app) {
  app.get('/api/seller', (req, res) => {
    res.json({
      // 这里是你的json内容
      errno: 0,
      data: seller
    })
  }),
  app.get('/api/goods', (req, res) => {
    res.json({
      // 这里是你的json内容
      errno: 0,
      data: goods
    })
  }),
  app.get('/api/ratings', (req, res) => {
    res.json({
      // 这里是你的json内容
      errno: 0,
      data: ratings
    })
  })
}

3:完整代码

'use strict'

//
// 通过express导入路由
const express = require('express')
const app = express()
var appData = require('../data.json')
// json卖家数据
var seller = appData.seller
// json商品数据
var goods = appData.goods
// json评论数据
var ratings = appData.ratings
// 编写路由
var apiRoutes = express.Router()
// 所有通过接口相关的api都会通过api这个路由导向到具体的路由
app.use('/api', apiRoutes)

//
const utils = require('./utils')
const webpack = require('webpack')
const config = require('../config')
const merge = require('webpack-merge')
const path = require('path')
const baseWebpackConfig = require('./webpack.base.conf')
const CopyWebpackPlugin = require('copy-webpack-plugin')
const HtmlWebpackPlugin = require('html-webpack-plugin')
const FriendlyErrorsPlugin = require('friendly-errors-webpack-plugin')
const portfinder = require('portfinder')

const HOST = process.env.HOST
const PORT = process.env.PORT && Number(process.env.PORT)

const devWebpackConfig = merge(baseWebpackConfig, {
  module: {
    rules: utils.styleLoaders({ sourceMap: config.dev.cssSourceMap, usePostCSS: true })
  },
  // cheap-module-eval-source-map is faster for development
  devtool: config.dev.devtool,

  // these devServer options should be customized in /config/index.js
  devServer: {
    // 找到devServer对象并在其后添加相关路由设置
    before (app) {
      app.get('/api/seller', function (req, res) {
        // 服务端收到请求后返回给客户端一个json数据
        res.json({
          // 当我们数据正常时，我们通过传递errno字符为0表示数据正常
          errno: 0,
          // 返回json中的卖家数据
          data: seller
        })
      })
      app.get('/api/goods', function (req, res) {
        res.json({
          errno: 0,
          data: goods
        })
      })
      app.get('/api/ratings', function (rea, res) {
        res.json({
          errno: 0,
          data: ratings
        })
      })
    },


    clientLogLevel: 'warning',
    historyApiFallback: {
      rewrites: [
        { from: /.*/, to: path.posix.join(config.dev.assetsPublicPath, 'index.html') },
      ],
    },
    hot: true,
    contentBase: false, // since we use CopyWebpackPlugin.
    compress: true,
    host: HOST || config.dev.host,
    port: PORT || config.dev.port,
    open: config.dev.autoOpenBrowser,
    overlay: config.dev.errorOverlay
      ? { warnings: false, errors: true }
      : false,
    publicPath: config.dev.assetsPublicPath,
    proxy: config.dev.proxyTable,
    quiet: true, // necessary for FriendlyErrorsPlugin
    watchOptions: {
      poll: config.dev.poll,
    }

    //





    //
  },
  plugins: [
    new webpack.DefinePlugin({
      'process.env': require('../config/dev.env')
    }),
    new webpack.HotModuleReplacementPlugin(),
    new webpack.NamedModulesPlugin(), // HMR shows correct file names in console on update.
    new webpack.NoEmitOnErrorsPlugin(),
    // https://github.com/ampedandwired/html-webpack-plugin
    new HtmlWebpackPlugin({
      filename: 'index.html',
      template: 'index.html',
      inject: true
    }),
    // copy custom static assets
    new CopyWebpackPlugin([
      {
        from: path.resolve(__dirname, '../static'),
        to: config.dev.assetsSubDirectory,
        ignore: ['.*']
      }
    ])
  ]
})

module.exports = new Promise((resolve, reject) => {
  portfinder.basePort = process.env.PORT || config.dev.port
  portfinder.getPort((err, port) => {
    if (err) {
      reject(err)
    } else {
      // publish the new Port, necessary for e2e tests
      process.env.PORT = port
      // add port to devServer config
      devWebpackConfig.devServer.port = port

      // Add FriendlyErrorsPlugin
      devWebpackConfig.plugins.push(new FriendlyErrorsPlugin({
        compilationSuccessInfo: {
          messages: [`Your application is running here: http://${devWebpackConfig.devServer.host}:${port}`],
        },
        onErrors: config.dev.notifyOnErrors
        ? utils.createNotifierCallback()
        : undefined
      }))

      resolve(devWebpackConfig)
    }
  })
})

前台resource调用

export default {

    data(){
      return {
        seller: {}
      }
    },
  created() {
    this.$http.get('/api/goods').then((result)=>{

        console.log("222")
        console.log(result.body)

    })
  },