将 UglifyJS 与 Preact、Webpack 2 一起使用时出现意外令牌错误

Question

我正在使用 Preact/ES6/Webpack 构建一个 Chrome 扩展。我使用两种配置之一进行打包：debug 使用 ESLint、Babel 和 CSS + JSON 加载器，prod 添加 2 个插件：UglifyJS 和 Zip。这是 webpack.config.js:

const webpack = require('webpack');
const path = require('path');
const CopyWebpackPlugin = require('copy-webpack-plugin');
const WebpackCleanupPlugin = require('webpack-cleanup-plugin');
const ZipPlugin = require('zip-webpack-plugin');
const manifest = require('./src/manifest');

let options = {
    // entry file - starting point for the app
    entry: {
    popup: './src/scripts/popup.js',
    options: './src/scripts/options.js',
    background: './src/scripts/background.js'
  },

    // where to dump the output of a production build
    output: {
    path: path.join(__dirname, 'build'),
    filename: 'scripts/[name].js'
  },

    module: {
        rules: [
      {
        test: /\.jsx?/i,
        exclude: /node_modules/,
        loader: 'eslint-loader',
        options: {
        },
        enforce: 'pre'
    },
    {
        test: /\.jsx?/i,
        exclude: /node_modules/,
        loader: 'babel-loader',
        options: {
            presets: [
            ['env', {
              'targets': {
                'chrome': 52
              }
            }]
          ],
            plugins: [
            ['transform-react-jsx'],
            ['module-resolver', {
              'root': ['.'],
              'alias': {
                'react': 'preact-compat',
                'react-dom': 'preact-compat'
              }
            }]
                    ]
                }
            },
      {
        test: /\.css$/,
        use: ['style-loader', 'css-loader']
      },
      {
        test: /\.json$/,
        use: 'json-loader'
      }
        ]
    },

  plugins: [
    new WebpackCleanupPlugin(),
    new CopyWebpackPlugin([
      {from: './src/_locales', to: '_locales'},
      {from: './src/icons', to: 'icons'},
      {from: './src/manifest.json', flatten: true},
      {from: './src/*.html', flatten: true}
    ])
  ],

    // enable Source Maps
    devtool: 'source-map',
};

if(process.env.NODE_ENV === 'production') {
  options.plugins.push(
    new webpack.optimize.UglifyJsPlugin({
      compress: {
        warnings: false,
        drop_console: false,
        screw_ie8: true,
        conditionals: true,
        unused: true,
        comparisons: true,
        sequences: true,
        dead_code: true,
        evaluate: true,
        if_return: true,
        join_vars: true,
      },
      output: {
        comments: false,
      },
    }),
    new ZipPlugin({
      path: '../dist',
      filename: `${manifest.name} ${manifest.version}.zip`
    })
  );
}

console.log(`This is a ${process.env.NODE_ENV === 'production' ? 'production' : 'development'} build with ${options.plugins.length} plugins`);

module.exports = options;

但是当我运行 prod 时，我得到以下错误：

ERROR in scripts/popup.js from UglifyJs
Unexpected token: name (getLatestValues) [scripts/popup.js:29428,4]

ERROR in scripts/options.js from UglifyJs
Unexpected token: name (getLatestValues) [scripts/options.js:29428,4]

ERROR in scripts/background.js from UglifyJs
Unexpected token: name (getLatestValues) [scripts/background.js:28678,4]

值得一提的是，getLatestResults 并不是我的代码中唯一一个前面有 await 的函数。此外，它应该只出现在 background.js 中，因为其他入口点不应该调用它。

另外值得一提的是，如果我只是注释 UglifyJS 代码，生成的压缩扩展效果很好。

我缺少什么配置来消除这些错误？

Answer 1

事实证明当前（5/2017）内置的webpack.optimize.UglifyJsPlugin不支持ES6。当 Babel 转译 await/async 时，它会将它们变成 generators，这会导致 UglifyJS 抛出错误。

this article 中列出了 UglifyJS 的几个替代方案，但我希望 Webpack 人员会更新插件，这样我就可以完整地保留我的代码。

TL;DR: 我的代码没问题； UglifyJS不支持ES6；以后会支持，或者会被alternative替代。

Answer 2

为了 ES6 兼容性，我已将 uglify-js 替换为 uglify-es：

https://www.npmjs.com/package/uglify-es

对我来说很好用！

将 UglifyJS 与 Preact、Webpack 2 一起使用时出现意外令牌错误

Unexpected Token error using UglifyJS with Preact, Webpack 2

javascript

uglifyjs

babeljs

webpack-2

preact