vue-cli的webpack模板项目配置文件分析

├─build
│ ├─build.js
│ ├─check-versions.js
│ ├─dev-client.js
│ ├─dev-server.js
│ ├─utils.js
│ ├─vue-loader.conf.js
│ ├─webpack.base.conf.js
│ ├─webpack.dev.conf.js
│ ├─webpack.prod.conf.js
│ └─webpack.test.conf.js
├─config
│ ├─dev.env.js
│ ├─index.js
│ ├─prod.env.js
│ └─test.env.js
├─...
└─package.json

"scripts": {
 "dev": "node build/dev-server.js",
 "build": "node build/build.js",
 "unit": "cross-env BABEL_ENV=test karma start test/unit/karma.conf.js --single-run",
 "e2e": "node test/e2e/runner.js",
 "test": "npm run unit && npm run e2e",
 "lint": "eslint --ext .js,.vue src test/unit/specs test/e2e/specs"
 }

// 检查NodeJS和npm的版本
require('./check-versions')()

// 获取配置
var config = require('../config')
// 如果Node的环境变量中没有设置当前的环境（NODE_ENV），则使用config中的配置作为当前的环境
if (!process.env.NODE_ENV) {
 process.env.NODE_ENV = JSON.parse(config.dev.env.NODE_ENV)
}

// 一个可以调用默认软件打开网址、图片、文件等内容的插件
// 这里用它来调用默认浏览器打开dev-server的端口，例如：localhost:8080
var opn = require('opn')
var path = require('path')
var express = require('express')
var webpack = require('webpack')

// 一个express中间件，用于将http请求代理到其他服务器
// 例：localhost:8080/api/xxx --> localhost:3000/api/xxx
// 这里使用该插件可以将前端开发中涉及到的请求代理到API服务器上，方便与服务器对接
var proxyMiddleware = require('http-proxy-middleware')

// 根据 Node 环境来引入相应的 webpack 配置
var webpackConfig = process.env.NODE_ENV === 'testing'
 ? require('./webpack.prod.conf')
 : require('./webpack.dev.conf')

// dev-server 端口，默认为config.dev.port设置的端口，即8080
var port = process.env.PORT || config.dev.port

// 用于判断是否要自动打开浏览器的布尔变量，当配置文件中没有设置自动打开浏览器的时候其值为 false
var autoOpenBrowser = !!config.dev.autoOpenBrowser

// 定义 HTTP 代理表，代理到 API 服务器
var proxyTable = config.dev.proxyTable

// 创建1个 express 实例
var app = express()

// 根据webpack配置文件创建Compiler对象
var compiler = webpack(webpackConfig)

// webpack-dev-middleware使用compiler对象来对相应的文件进行编译和绑定
// 编译绑定后将得到的产物存放在内存中而没有写进磁盘
// 将这个中间件交给express使用之后即可访问这些编译后的产品文件
var devMiddleware = require('webpack-dev-middleware')(compiler, {
 publicPath: webpackConfig.output.publicPath,
 quiet: true
})

// webpack-hot-middleware，用于实现热重载功能的中间件
var hotMiddleware = require('webpack-hot-middleware')(compiler, {
 log: () => {}
})

// 当html-webpack-plugin提交之后通过热重载中间件发布重载动作使得页面重载
compiler.plugin('compilation', function (compilation) {
 compilation.plugin('html-webpack-plugin-after-emit', function (data, cb) {
 hotMiddleware.publish({ action: 'reload' })
 cb()
 })
})

// 将 proxyTable 中的代理请求配置挂在到express服务器上
Object.keys(proxyTable).forEach(function (context) {
 var options = proxyTable[context]
 // 格式化options，例如将'www.example.com'变成{ target: 'www.example.com' }
 if (typeof options === 'string') {
 options = { target: options }
 }
 app.use(proxyMiddleware(options.filter || context, options))
})

// handle fallback for HTML5 history API
// 重定向不存在的URL，常用于SPA
app.use(require('connect-history-api-fallback')())

// serve webpack bundle output
// 使用webpack开发中间件
// 即将webpack编译后输出到内存中的文件资源挂到express服务器上
app.use(devMiddleware)

// enable hot-reload and state-preserving
// compilation error display
// 将热重载中间件挂在到express服务器上
app.use(hotMiddleware)

// serve pure static assets
// 静态资源的路径
var staticPath = path.posix.join(config.dev.assetsPublicPath, config.dev.assetsSubDirectory)

// 将静态资源挂到express服务器上
app.use(staticPath, express.static('./static'))

// 应用的地址信息，例如：http://localhost:8080
var uri = 'http://localhost:' + port

// webpack开发中间件合法（valid）之后输出提示语到控制台，表明服务器已启动
devMiddleware.waitUntilValid(function () {
 console.log('> Listening at ' + uri + '\n')
})

// 启动express服务器相应的端口（8080）
module.exports = app.listen(port, function (err) {
 if (err) {
 console.log(err)
 return
 }

 // when env is testing, don't need open it
 // 如果符合自动打开浏览器的条件，则通过opn插件调用系统默认浏览器打开对应的地址uri
 if (autoOpenBrowser && process.env.NODE_ENV !== 'testing') {
 opn(uri)
 }
})

var path = require('path')
var utils = require('./utils')
var config = require('../config')
var vueLoaderConfig = require('./vue-loader.conf')

// 给出正确的绝对路径
function resolve (dir) {
 return path.join(__dirname, '..', dir)
}

module.exports = {
 // 配置webpack编译入口
 entry: {
 app: './src/main.js'
 },

 // 配置webpack输出路径和命名规则
 output: {
 // webpack输出的目标文件夹路径（例如：/dist）
 path: config.build.assetsRoot,
 // webpack输出bundle文件命名格式
 filename: '[name].js',
 // webpack编译输出的发布路径
 publicPath: process.env.NODE_ENV === 'production'
  ? config.build.assetsPublicPath
  : config.dev.assetsPublicPath
 },

 // 配置模块resolve的规则
 resolve: {
 // 自动resolve的扩展名
 extensions: ['.js', '.vue', '.json'],
 // resolve模块的时候要搜索的文件夹
 modules: [
  resolve('src'),
  resolve('node_modules')
 ],
 // 创建路径别名，有了别名之后引用模块更方便，例如
 // import Vue from 'vue/dist/vue.common.js'可以写成 import Vue from 'vue'
 alias: {
  'vue$': 'vue/dist/vue.common.js',
  'src': resolve('src'),
  'assets': resolve('src/assets'),
  'components': resolve('src/components')
 }
 },
 // 配置不同类型模块的处理规则
 module: {
 rules: [
  {// 对src和test文件夹下的.js和.vue文件使用eslint-loader
  test: /\.(js|vue)$/,
  loader: 'eslint-loader',
  enforce: "pre",
  include: [resolve('src'), resolve('test')],
  options: {
   formatter: require('eslint-friendly-formatter')
  }
  },
  {// 对所有.vue文件使用vue-loader
  test: /\.vue$/,
  loader: 'vue-loader',
  options: vueLoaderConfig
  },
  {// 对src和test文件夹下的.js文件使用babel-loader
  test: /\.js$/,
  loader: 'babel-loader',
  include: [resolve('src'), resolve('test')]
  },
  {// 对图片资源文件使用url-loader，query.name指明了输出的命名规则
  test: /\.(png|jpe?g|gif|svg)(\?.*)?$/,
  loader: 'url-loader',
  query: {
   limit: 10000,
   name: utils.assetsPath('img/[name].[hash:7].[ext]')
  }
  },
  {// 对字体资源文件使用url-loader，query.name指明了输出的命名规则
  test: /\.(woff2?|eot|ttf|otf)(\?.*)?$/,
  loader: 'url-loader',
  query: {
   limit: 10000,
   name: utils.assetsPath('fonts/[name].[hash:7].[ext]')
  }
  }
 ]
 }
}

var utils = require('./utils')
var webpack = require('webpack')
var config = require('../config')

// 一个可以合并数组和对象的插件
var merge = require('webpack-merge')
var baseWebpackConfig = require('./webpack.base.conf')

// 一个用于生成HTML文件并自动注入依赖文件（link/script）的webpack插件
var HtmlWebpackPlugin = require('html-webpack-plugin')

// 用于更友好地输出webpack的警告、错误等信息
var FriendlyErrorsPlugin = require('friendly-errors-webpack-plugin')

// add hot-reload related code to entry chunks
Object.keys(baseWebpackConfig.entry).forEach(function (name) {
 baseWebpackConfig.entry[name] = ['./build/dev-client'].concat(baseWebpackConfig.entry[name])
})

// 合并基础的webpack配置
module.exports = merge(baseWebpackConfig, {
 // 配置样式文件的处理规则，使用styleLoaders
 module: {
 rules: utils.styleLoaders({ sourceMap: config.dev.cssSourceMap })
 },

 // 配置Source Maps。在开发中使用cheap-module-eval-source-map更快
 devtool: '#cheap-module-eval-source-map',

 // 配置webpack插件
 plugins: [
 new webpack.DefinePlugin({
  'process.env': config.dev.env
 }),
 // https://github.com/glenjamin/webpack-hot-middleware#installation--usage
 new webpack.HotModuleReplacementPlugin(),
 // 后页面中的报错不会阻塞，但是会在编译结束后报错
 new webpack.NoEmitOnErrorsPlugin(),
 // https://github.com/ampedandwired/html-webpack-plugin
 new HtmlWebpackPlugin({
  filename: 'index.html',
  template: 'index.html',
  inject: true
 }),
 new FriendlyErrorsPlugin()
 ]
})

var utils = require('./utils')
var config = require('../config')
var isProduction = process.env.NODE_ENV === 'production'

module.exports = {
 // css加载器
 loaders: utils.cssLoaders({
 sourceMap: isProduction
  ? config.build.productionSourceMap
  : config.dev.cssSourceMap,
 extract: isProduction
 }),
 // 编译css之后自动添加前缀
 postcss: [
 require('autoprefixer')({
  browsers: ['last 2 versions']
 })
 ]
}

// https://github.com/shelljs/shelljs
// 检查NodeJS和npm的版本
require('./check-versions')()

process.env.NODE_ENV = 'production'

// Elegant terminal spinner
var ora = require('ora')
var path = require('path')

// 用于在控制台输出带颜色字体的插件
var chalk = require('chalk')

// 执行Unix命令行的插件
var shell = require('shelljs')
var webpack = require('webpack')
var config = require('../config')
var webpackConfig = require('./webpack.prod.conf')

var spinner = ora('building for production...')
spinner.start() // 开启loading动画

// 输出文件的目标文件夹
var assetsPath = path.join(config.build.assetsRoot, config.build.assetsSubDirectory)

// 递归删除旧的目标文件夹
shell.rm('-rf', assetsPath)

// 重新创建文件夹 
shell.mkdir('-p', assetsPath)
shell.config.silent = true
// 将static文件夹复制到输出的目标文件夹
shell.cp('-R', 'static/*', assetsPath)
shell.config.silent = false

// webpack编译
webpack(webpackConfig, function (err, stats) {
 spinner.stop() // 停止loading动画
 if (err) throw err
 // 没有出错则输出相关信息
 process.stdout.write(stats.toString({
 colors: true,
 modules: false,
 children: false,
 chunks: false,
 chunkModules: false
 }) + '\n\n')
 console.log(chalk.cyan(' Build complete.\n'))
 console.log(chalk.yellow(
 ' Tip: built files are meant to be served over an HTTP server.\n' +
 ' Opening index.html over file:// won\'t work.\n'
 ))
})

var path = require('path')
var utils = require('./utils')
var webpack = require('webpack')
var config = require('../config')
var merge = require('webpack-merge')
var baseWebpackConfig = require('./webpack.base.conf')
var HtmlWebpackPlugin = require('html-webpack-plugin')

// 用于从webpack生成的bundle中提取文本到特定文件中的插件
// 可以抽取出css，js文件将其与webpack输出的bundle分离
var ExtractTextPlugin = require('extract-text-webpack-plugin')

var env = process.env.NODE_ENV === 'testing'
 ? require('../config/test.env')
 : config.build.env

// 合并基础的webpack配置
var webpackConfig = merge(baseWebpackConfig, {
 module: {
 rules: utils.styleLoaders({
  sourceMap: config.build.productionSourceMap,
  extract: true
 })
 },
 devtool: config.build.productionSourceMap ? '#source-map' : false,
 // 配置webpack的输出
 output: {
 // 编译输出目录
 path: config.build.assetsRoot,
 // 编译输出文件名格式
 filename: utils.assetsPath('js/[name].[chunkhash].js'),
 // 没有指定输出名的文件输出的文件名格式
 chunkFilename: utils.assetsPath('js/[id].[chunkhash].js')
 },

 // 配置webpack插件
 plugins: [
 // http://vuejs.github.io/vue-loader/en/workflow/production.html
 new webpack.DefinePlugin({
  'process.env': env
 }),

 // 压缩代码
 new webpack.optimize.UglifyJsPlugin({
  compress: {
  warnings: false
  },
  sourceMap: true
 }),

 // 抽离css文件
 new ExtractTextPlugin({
  filename: utils.assetsPath('css/[name].[contenthash].css')
 }),

 // generate dist index.html with correct asset hash for caching.
 // you can customize output by editing /index.html
 // see https://github.com/ampedandwired/html-webpack-plugin
 new HtmlWebpackPlugin({
  filename: process.env.NODE_ENV === 'testing'
  ? 'index.html'
  : config.build.index,
  template: 'index.html',
  inject: true,
  minify: {
  removeComments: true,
  collapseWhitespace: true,
  removeAttributeQuotes: true
  // more options:
  // https://github.com/kangax/html-minifier#options-quick-reference
  },
  // necessary to consistently work with multiple chunks via CommonsChunkPlugin
  chunksSortMode: 'dependency'
 }),

 // split vendor js into its own file
 new webpack.optimize.CommonsChunkPlugin({
  name: 'vendor',
  minChunks: function (module, count) {
  // any required modules inside node_modules are extracted to vendor
  return (
   module.resource &&
   /\.js$/.test(module.resource) &&
   module.resource.indexOf(
   path.join(__dirname, '../node_modules')
   ) === 0
  )
  }
 }),
 // extract webpack runtime and module manifest to its own file in order to
 // prevent vendor hash from being updated whenever app bundle is updated
 new webpack.optimize.CommonsChunkPlugin({
  name: 'manifest',
  chunks: ['vendor']
 })
 ]
})

// gzip模式下需要引入compression插件进行压缩
if (config.build.productionGzip) {
 var CompressionWebpackPlugin = require('compression-webpack-plugin')
 webpackConfig.plugins.push(
 new CompressionWebpackPlugin({
  asset: '[path].gz[query]',
  algorithm: 'gzip',
  test: new RegExp(
  '\\.(' +
  config.build.productionGzipExtensions.join('|') +
  ')$'
  ),
  threshold: 10240,
  minRatio: 0.8
 })
 )
}

if (config.build.bundleAnalyzerReport) {
 var BundleAnalyzerPlugin = require('webpack-bundle-analyzer').BundleAnalyzerPlugin
 webpackConfig.plugins.push(new BundleAnalyzerPlugin())
}

module.exports = webpackConfig

// 用于在控制台输出带颜色字体的插件
var chalk = require('chalk')

// 语义化版本检查插件（The semantic version parser used by npm）
var semver = require('semver')

// 引入package.json
var packageConfig = require('../package.json')

// 开辟子进程执行指令cmd并返回结果
function exec (cmd) {
 return require('child_process').execSync(cmd).toString().trim()
}

// node和npm版本需求
var versionRequirements = [
 {
 name: 'node',
 currentVersion: semver.clean(process.version),
 versionRequirement: packageConfig.engines.node
 },
 {
 name: 'npm',
 currentVersion: exec('npm --version'),
 versionRequirement: packageConfig.engines.npm
 }
]

module.exports = function () {
 var warnings = []
 // 依次判断版本是否符合要求
 for (var i = 0; i < versionRequirements.length; i++) {
 var mod = versionRequirements[i]
 if (!semver.satisfies(mod.currentVersion, mod.versionRequirement)) {
  warnings.push(mod.name + ': ' +
  chalk.red(mod.currentVersion) + ' should be ' +
  chalk.green(mod.versionRequirement)
  )
 }
 }
 // 如果有警告则将其输出到控制台
 if (warnings.length) {
 console.log('')
 console.log(chalk.yellow('To use this template, you must update following to modules:'))
 console.log()
 for (var i = 0; i < warnings.length; i++) {
  var warning = warnings[i]
  console.log(' ' + warning)
 }
 console.log()
 process.exit(1)
 }
}

// see http://vuejs-templates.github.io/webpack for documentation.
var path = require('path')

module.exports = {
 // 构建产品时使用的配置
 build: {
 // webpack的编译环境
 env: require('./prod.env'),
 // 编译输入的index.html文件
 index: path.resolve(__dirname, '../dist/index.html'),
 // webpack输出的目标文件夹路径
 assetsRoot: path.resolve(__dirname, '../dist'),
 // webpack编译输出的二级文件夹
 assetsSubDirectory: 'static',
 // webpack编译输出的发布路径
 assetsPublicPath: '/',
 // 使用SourceMap
 productionSourceMap: true,
 // Gzip off by default as many popular static hosts such as
 // Surge or Netlify already gzip all static assets for you.
 // Before setting to `true`, make sure to:
 // npm install --save-dev compression-webpack-plugin
 // 默认不打开开启gzip模式
 productionGzip: false,
 // gzip模式下需要压缩的文件的扩展名
 productionGzipExtensions: ['js', 'css'],
 // Run the build command with an extra argument to
 // View the bundle analyzer report after build finishes:
 // `npm run build --report`
 // Set to `true` or `false` to always turn it on or off
 bundleAnalyzerReport: process.env.npm_config_report
 },
 // 开发过程中使用的配置
 dev: {
 // webpack的编译环境
 env: require('./dev.env'),
 // dev-server的端口
 port: 8080,
 // 启动dev-server之后自动打开浏览器
 autoOpenBrowser: true,
 // webpack编译输出的二级文件夹
 assetsSubDirectory: 'static',
 // webpack编译输出的发布路径
 assetsPublicPath: '/',
 // 请求代理表，在这里可以配置特定的请求代理到对应的API接口
 // 例如将'/api/xxx'代理到'www.example.com/api/xxx'
 proxyTable: {},
 // CSS Sourcemaps off by default because relative paths are "buggy"
 // with this option, according to the CSS-Loader README
 // (https://github.com/webpack/css-loader#sourcemaps)
 // In our experience, they generally work as expected,
 // just be aware of this issue when enabling this option.
 // 是否开启 cssSourceMap
 cssSourceMap: false
 }
}