基于 webpack 2 构建的 dev-server

大江东去。

source: vue-cli 开源项目

// *package.json*
{
   "start": node dev-server.js
}



// *config/index.js*

// see http://vuejs-templates.github.io/webpack for documentation.
var path = require('path')
// 默认配置
var build = {
  env: require('./prod.env'),
  index: path.resolve(__dirname, '../dist/index.html'),
  assetsRoot: path.resolve(__dirname, '../dist'),
  assetsSubDirectory: 'static',
  assetsPublicPath: '/',
  /*
   12.29 设置生产环境下 sourceMap为false
   */
  productionSourceMap: false,
  // 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
  productionGzip: false,
  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
}
var dev = {
  env: require('./dev.env'),
  port: 8080,
  autoOpenBrowser: true,
  assetsSubDirectory: 'static',
  assetsPublicPath: '/',
  proxyTable: {
    '/api': {
      target: 'http://localhost:8088/api/',
      changeOrigin: false,
      pathRewrite: {
        '^/api': ''
      }
    }
  },
  // 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.
  cssSourceMap: false
}
// 加载本地配置文件
try {
  var local_settings = require('./local_settings.env')
} catch (err) {}
// 使用本地配置替换默认配置
if (local_settings) {
  build = local_settings.build
  dev = local_settings.dev
}

module.exports = {
  build: build,
  dev: dev
}



// dev-server.js
require('./check-versions')()

var config = require('../config')
if (!process.env.NODE_ENV) {
  process.env.NODE_ENV = JSON.parse(config.dev.env.NODE_ENV)
}

var opn = require('opn')
var path = require('path')
var express = require('express')
var webpack = require('webpack')
var proxyMiddleware = require('http-proxy-middleware')
var webpackConfig = require('./webpack.dev.conf')

// default port where dev server listens for incoming traffic
var port = process.env.PORT || config.dev.port
// automatically open browser, if not set will be false
var autoOpenBrowser = !!config.dev.autoOpenBrowser
// Define HTTP proxies to your custom API backend
// https://github.com/chimurai/http-proxy-middleware
var proxyTable = config.dev.proxyTable

var app = express()
var compiler = webpack(webpackConfig)

var devMiddleware = require('webpack-dev-middleware')(compiler, {
  publicPath: webpackConfig.output.publicPath,
  quiet: true
})

var hotMiddleware = require('webpack-hot-middleware')(compiler, {
  log: () => {}
})
// force page reload when html-webpack-plugin template changes
compiler.plugin('compilation', function (compilation) {
  compilation.plugin('html-webpack-plugin-after-emit', function (data, cb) {
    hotMiddleware.publish({ action: 'reload' })
    cb()
  })
})

// proxy api requests
Object.keys(proxyTable).forEach(function (context) {
  var options = proxyTable[context]
  if (typeof options === 'string') {
    options = { target: options }
  }
  /*
    context = '/api'
    options = {
      target: 'http://localhost:8088/api/',
      changeOrigin: false,
      pathRewrite: {
        '^/api': ''
      }
    }
  */
  app.use(proxyMiddleware(options.filter || context, options))
})

// handle fallback for HTML5 history API
app.use(require('connect-history-api-fallback')())

// serve webpack bundle output
app.use(devMiddleware)

// enable hot-reload and state-preserving
// compilation error display
app.use(hotMiddleware)

// serve pure static assets
var staticPath = path.posix.join(config.dev.assetsPublicPath, config.dev.assetsSubDirectory)
app.use(staticPath, express.static('./static'))

var uri = 'http://localhost:' + port

var _resolve
var readyPromise = new Promise(resolve => {
  _resolve = resolve
})

console.log('> Starting dev server...')
devMiddleware.waitUntilValid(() => {
  console.log('> Listening at ' + uri + '\n')
  // when env is testing, don't need open it
  if (autoOpenBrowser && process.env.NODE_ENV !== 'testing') {
    opn(uri)
  }
  _resolve()
})

var server = app.listen(port)

module.exports = {
  ready: readyPromise,
  close: () => {
    server.close()
  }
}


// *webpack.dev.conf.js*
var utils = require('./utils')
var webpack = require('webpack')
var config = require('../config')
var merge = require('webpack-merge')
// 略
var baseWebpackConfig = require('./webpack.base.conf')
var HtmlWebpackPlugin = require('html-webpack-plugin')
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])
})

module.exports = merge(baseWebpackConfig, {
  module: {
    rules: utils.styleLoaders({ sourceMap: config.dev.cssSourceMap })
  },
  // cheap-module-eval-source-map is faster for development
  devtool: '#cheap-module-eval-source-map',
  plugins: [
    new webpack.DefinePlugin({
      'process.env': config.dev.env
    }),
    // https://github.com/glenjamin/webpack-hot-middleware#installation--usage
    new webpack.HotModuleReplacementPlugin(),
    new webpack.NoEmitOnErrorsPlugin(),
    // https://github.com/ampedandwired/html-webpack-plugin
    new HtmlWebpackPlugin({
      filename: 'index.html',
      template: 'index.html',
      inject: true
    }),
    new FriendlyErrorsPlugin()
  ]
})