使用 babel 缩小 webpack 中的 ES6 代码

2024-04-13

我尝试过 Uglifyjs、babelli (babel-minify ) 等选项。似乎没有任何效果。Uglify 抛出一些如下错误：

预期名称 [au680.bundle.js:147541,22]

babelli 也不压缩代码。任何人都可以给出使用 webpack 2 babel 进行 es6 压缩的简单示例吗？可能是一个可以干净地完成工作的插件。

var path = require('path');
var webpack = require('webpack');
var HtmlWebpackPlugin = require('html-webpack-plugin');
var AppCachePlugin = require('appcache-webpack-plugin');

var appConfig= require('./config.js');
console.log("appConfig is ->>>",appConfig);
var appPort = appConfig.APP_PORT;//Port on which the application is running

process.noDeprecation = true;
var ASSET_PATH = '/'
module.exports = function(options) {
  var entry, jsLoaders, plugins, cssLoaders, devtool;
  console.log('options webconfig-->', options, 'directory name', __dirname);

  // If production is true
  if (options.prod) {
    console.log('production minification');
    // Entry
    entry = {
       veris:path.resolve(__dirname,'./VerisInstrument/js/VerisApp.js'),
       au680 : path.resolve(__dirname,'./Au680Instrument/js/au680App.js'),
	   commondashboard:path.resolve(__dirname,'./CommonDashboard/js/CommonDashboardApp.js'),
       groups:path.resolve(__dirname,'./Groups/js/GroupsApp.js'),
       homepage : path.resolve(__dirname,'./HomePage/js/HomePageApp.js'),
       infohealthcheck : path.resolve(__dirname,'./Common/js/infohealthcheckapp.js')
      
    };

   
    // Plugins
    plugins = [// Plugins for Webpack
    new webpack.DefinePlugin({
    'process.env': {
      'NODE_ENV': JSON.stringify('production')
    }
   }),
  //   new webpack.optimize.UglifyJsPlugin({minimize: true,comments : false,compress: {
  //   // remove warnings
  //   warnings: false,

  //   // Drop console statements
  //   drop_console: true
  // }})

    
      // new es3MemberExpressionLiterals(),
      //
      
    ];

  // If app is in development
  } else {
    devtool = 'source-map';
    // Entry
    // entry = [
    //   "webpack-dev-server/client?http://0.0.0.0:" + appPort, // Needed for hot reloading
    //   "webpack/hot/only-dev-server", // See above
    //   //path.resolve(__dirname,'./app') // Start with js/app.js...
    //   path.resolve(__dirname,'./VerisInstrument/js/VerisApp')
    // ];
  //   require("babel-core").transform("code", {
  //   plugins: ["transform-object-rest-spread"]
  // });
    entry = {
      main: [
        "webpack-dev-server/client?http://0.0.0.0:" + appPort, // Needed for hot reloading
        "webpack/hot/only-dev-server" // See above
      ],
      //path.resolve(__dirname,'./js/app') // Start with js/app.js...
     veris : path.resolve(__dirname,'./VerisInstrument/js/VerisApp'),
      au680 : path.resolve(__dirname,'./Au680Instrument/js/au680App.js'),
	  commondashboard:path.resolve(__dirname,'./CommonDashboard/js/CommonDashboardApp.js'),
      groups:path.resolve(__dirname,'./Groups/js/GroupsApp.js'),
      homepage : path.resolve(__dirname,'./HomePage/js/HomePageApp.js'),
      infohealthcheck : path.resolve(__dirname,'./Common/js/infohealthcheckapp.js')
      
    };
    
    // Only plugin is the hot module replacement plugin
    plugins = [
     new webpack.DefinePlugin({
    'process.env': {
      'NODE_ENV': JSON.stringify('development'),
      }
     }),
     new webpack.HotModuleReplacementPlugin()// Make hot loading work,
    ]
  }

  return {
    devtool: devtool,
    entry: entry,
    // output: { // Compile into js/build.js
    //   path: path.resolve(__dirname, 'build'),
    //   filename: "js/bundle.js",
    //   publicPath : '/'
    // },
    output: { // Compile into js/build.js
      path: path.resolve(__dirname, 'build'),
      filename: '[name].bundle.js',
      publicPath : ASSET_PATH
    },
    module: {
      rules: [
      {
          test: /\.js$/, // Transform all .js files required somewhere within an entry point...
          loader: 'babel-loader', // ...with the specified loaders...
          exclude: /node_modules/,
          options: {
          presets: ['es2015','react','stage-2','env'],
          plugins: [require('babel-plugin-transform-object-rest-spread'),require('babel-plugin-transform-es2015-destructuring'),require('babel-plugin-transform-es2015-parameters')]
        }
          // query : {
          //   presets : ['es2015','react','stage-2','env']
          // }

        }
        , {
          test:   /\.css$/, // Transform all .css files required somewhere within an entry point...
          use : [
            {
              loader : 'style-loader'
            },
            {
              loader : 'css-loader'
            },
            {
              loader : 'postcss-loader'
            },
            {
              loader: 'sass-loader'
            }
          ] // ...with PostCSS
        }, {
          test: /\.jpe?g$|\.gif$|\.png$/i,
          loader: "url-loader?limit=100000"
        },
        { test: /\.(woff|woff2|eot|ttf|svg)$/,
         loader: 'url-loader?limit=100000' }
      ]
    },
    plugins: plugins,
    target: "web", // Make web variables accessible to webpack, e.g. window
    stats: false, // Don't show stats in the console
    node: {
      fs: "empty"
    }
  }
}

Update

如果您不担心支持旧版浏览器，webpack v4+ 将在生产模式下默认缩小代码 https://webpack.js.org/guides/production/#minification:

webpack --mode=production

之前的回答

From https://github.com/webpack/webpack/issues/2545 https://github.com/webpack/webpack/issues/2545:

问题是 UglifyJS 还不支持 ES6，所以还无法避免这种转换。您可以在以下位置关注进度meesho/UglifyJS 2#448 https://github.com/mishoo/UglifyJS2/issues/448 .

解决办法有很多种；这里有几个：

首先转译 ES6 代码，然后缩小它
为了获得最大的兼容性，请使用 Babel 进行转译，然后使用 Babel Minify（以前称为 Babili）进行缩小：

Install 巴别塔装载机 https://github.com/babel/babel-loader and babel-minify-webpack-插件 https://github.com/webpack-contrib/babel-minify-webpack-plugin
```
npm install babel-loader babel-minify-webpack-plugin --save-dev
```
Or:
```
yarn add babel-loader babel-minify-webpack-plugin --dev
```

将其添加到 webpack.config.js 中：

const MinifyPlugin = require('babel-minify-webpack-plugin');

module.exports = {
  // ...
  module: {
    rules: [
      {
        test: /\.js$/,
        use: {
          loader: 'babel-loader',
          options: {
            presets: ['env']
          }
        }
      }
    ]
  },
  plugins: [
    new MinifyPlugin()
  ]
};

或者，如果您愿意，可以使用 UglifyJS 而不是 Babel Minify：

const MinifyPlugin = require('uglifyjs-webpack-plugin');

无需转译即可缩小 ES6 代码
为了仅与支持您正在使用的 ES6 功能的浏览器兼容，请使用 Babel Minify 进行缩小而不进行转译：

Install babel-minify-webpack-插件 https://github.com/webpack-contrib/babel-minify-webpack-plugin
```
npm install babel-minify-webpack-plugin --save-dev
```
Or:
```
yarn add babel-minify-webpack-plugin --dev
```

将其添加到 webpack.config.js 中：

const MinifyPlugin = require('babel-minify-webpack-plugin');

module.exports = {
  // ...
  plugins: [
    new MinifyPlugin()
  ]
};

Babel Minify 的默认设置对我来说效果很好，但您可以在此处查看更多可以自定义的选项：https://github.com/webpack-contrib/babel-minify-webpack-plugin https://github.com/webpack-contrib/babel-minify-webpack-plugin

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