1. 上package.json

"dependencies": {
    "vue": "^2.6.10"
  },
  "devDependencies": {
    "@babel/core": "^7.5.0",
    "@babel/plugin-syntax-dynamic-import": "^7.2.0",
    "@babel/preset-env": "^7.5.2",
    "babel-loader": "^8.0.6",
    "clean-webpack-plugin": "^3.0.0",
    "css-loader": "^3.0.0",
    "html-webpack-plugin": "^3.2.0",
    "mini-css-extract-plugin": "^0.7.0",
    "url-loader": "^2.0.1",
    "vue-loader": "^15.7.0",
    "vue-style-loader": "^4.1.2",
    "vue-template-compiler": "^2.6.10",
    "webpack": "^4.35.3",
    "webpack-cli": "^3.3.5",
    "webpack-dev-server": "^3.7.2",
    "webpack-merge": "^4.2.1"
  }

2. webpack common

const path = require('path');
const VueLoaderPlugin = require('vue-loader/lib/plugin');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const { CleanWebpackPlugin } = require("clean-webpack-plugin");

module.exports = {
  entry: {
    app: './src/main.js'
  },
  output: {
    filename: '[name].[hash].bundle.js',
    path: path.join(__dirname, './dist')
  },
  module: {
    rules: [
      {
        test: /\.vue$/,
        use: ['vue-loader']
      },
      {
        test: /\.(png|jpg|gif)$/,
        use: [
          {
            loader: 'url-loader',
            options: {
              limit: 8192  // 小于8192byte 打成base64
            }
          }
        ]
      },
      {
        test: /\.js$/,
        use: ['babel-loader'],
        exclude: /node_modules/
      }
    ]
  },
  plugins: [
    new HtmlWebpackPlugin({
      template: 'template.html',
      filename: 'index.html'
    }),
    new VueLoaderPlugin(),
    new CleanWebpackPlugin()
  ],
  resolve: {  //导入的时候不用写拓展名
    extensions: [' ', '.js', '.json', '.vue', '.scss', '.css']
  },
}

3. webpack dev

const merge = require('webpack-merge');
const common = require('./webpack.common.js');

module.exports = merge(common, {
  mode: 'development',
  devtool: 'source-map',
  module: {
    rules: [
      {
        test: /\.css$/,
        use: ['vue-style-loader', 'css-loader']
      }
    ]
  },
  watchOptions: {
    ignored: /node_modules/,
    aggregateTimeout: 300, //300ms内重复保存不打包
    poll: 1000  //每秒询问的文件变更的次数
  },
  devServer: {
    inline: true,
    compress: true,
    host: '127.0.0.1',
    port: 2500,
    historyApiFallback: true
  }
})

4. webpack prod

const merge = require('webpack-merge');
const common = require('./webpack.common.js');
const MiniCssExtractPlugin = require('mini-css-extract-plugin')

module.exports = merge(common, {
  mode: 'production',
  module: {
    rules: [
      {
        test: /\.css$/,
        use: [
          {
            loader: MiniCssExtractPlugin.loader   //外链 css
          },
          'css-loader'
        ]
      }
    ]
  },
  plugins: [
    new MiniCssExtractPlugin({
      filename: 'style.css'
    })
  ]
})

5. .babelrc

{
  "plugins": ["@babel/plugin-syntax-dynamic-import"],
  "presets": ["@babel/preset-env"]
}