vue-cli 引入jQuery，Bootstrap，popper的方法

npm install jquery --save     //jquery插件npm install bootstrap --save    //bootstrapnpm install --save popper.js   //popper.js

plugins: [  new webpack.optimize.CommonsChunkPlugin('common'),  new webpack.ProvidePlugin({   $: 'jquery',   jQuery: 'jquery',   Popper: ['popper.js', 'default']  }) ]

'use strict'const path = require('path')const utils = require('./utils')const config = require('../config')const vueLoaderConfig = require('./vue-loader.conf')const webpack = require('webpack')function resolve (dir) { return path.join(__dirname, '..', dir)} module.exports = { context: path.resolve(__dirname, '../'), entry: {  app: './src/main.js' }, output: {  path: config.build.assetsRoot,  filename: '[name].js',  publicPath: process.env.NODE_ENV === 'production'   ? config.build.assetsPublicPath   : config.dev.assetsPublicPath }, resolve: {  extensions: ['.js', '.vue', '.json'],  alias: {   'vue$': 'vue/dist/vue.esm.js',   '@': resolve('src'),  } }, module: {  rules: [   {    test: //.vue$/,    loader: 'vue-loader',    options: vueLoaderConfig   },   {    test: //.js$/,    loader: 'babel-loader',    include: [resolve('src'), resolve('test'), resolve('node_modules/webpack-dev-server/client')]   },   {    test: //.(png|jpe?g|gif|svg)(/?.*)?$/,    loader: 'url-loader',    options: {     limit: 10000,     name: utils.assetsPath('img/[name].[hash:7].[ext]')    }   },   {    test: //.(mp4|webm|ogg|mp3|wav|flac|aac)(/?.*)?$/,    loader: 'url-loader',    options: {     limit: 10000,     name: utils.assetsPath('media/[name].[hash:7].[ext]')    }   },   {    test: //.(woff2?|eot|ttf|otf)(/?.*)?$/,    loader: 'url-loader',    options: {     limit: 10000,     name: utils.assetsPath('fonts/[name].[hash:7].[ext]')    }   }  ] }, node: {  // prevent webpack from injecting useless setImmediate polyfill because Vue  // source contains it (although only uses it if it's native).  setImmediate: false,  // prevent webpack from injecting mocks to Node native modules  // that does not make sense for the client  dgram: 'empty',  fs: 'empty',  net: 'empty',  tls: 'empty',  child_process: 'empty' }, plugins: [  new webpack.optimize.CommonsChunkPlugin('common'),  new webpack.ProvidePlugin({   $: 'jquery',   jQuery: 'jquery',   Popper: ['popper.js', 'default']  }) ]}

import $ from 'jquery'import 'bootstrap/dist/css/bootstrap.min.css'import 'bootstrap/dist/js/bootstrap.min'

npm run dev