webpack学习

贴出项目中webpack相关配置，逐个解析

1. 生产环境配置 webpack.config.prod.js

var autoprefixer = require('autoprefixer');
var webpack = require('webpack');
var HtmlWebpackPlugin = require('html-webpack-plugin');
var ExtractTextPlugin = require('extract-text-webpack-plugin');
var ManifestPlugin = require('webpack-manifest-plugin');
var InterpolateHtmlPlugin = require('react-dev-utils/InterpolateHtmlPlugin');
var url = require('url');
var paths = require('./paths');
var getClientEnvironment = require('./env');
var alias = require('./alias');

function ensureSlash(path, needsSlash) {
  var hasSlash = path.endsWith('/');
  if (hasSlash && !needsSlash) {
    return path.substr(path, path.length - 1);
  } else if (!hasSlash && needsSlash) {
    return path + '/';
  } else {
    return path;
  }
}
var homepagePath = require(paths.appPackageJson).homepage;
var homepagePathname = homepagePath ? url.parse(homepagePath).pathname : '/';
var publicPath = ensureSlash(homepagePathname, true);
var publicUrl = ensureSlash(homepagePathname, false);
var env = getClientEnvironment(publicUrl);

if (env['process.env'].NODE_ENV !== '"production"') {
  throw new Error('Production builds must have NODE_ENV=production.');
}

module.exports = {
  bail: true,
  devtool: 'source-map',
  entry: {
    common: [
      require.resolve('react-dev-utils/webpackHotDevClient'),
      require.resolve('./polyfills'),
      paths.appIndexJs
    ],
    zh_CN: paths.i18n['zh-CN'],
    en_US: paths.i18n['en-US']
  },
  output: {
    path: paths.appBuild,
    filename: 'static/js/[name].[chunkhash:8].js',
    chunkFilename: 'static/js/[name].[chunkhash:8].chunk.js',
    publicPath: publicPath
  },
  resolve: {
    fallback: paths.nodePaths,
    extensions: ['.js', '.json', '.jsx', ''],
    alias
  },

  module: {
    preLoaders: [
      {
        test: /.(js|jsx)$/,
        loader: 'eslint',
        include: paths.appSrc
      }
    ],
    loaders: [
      {
        exclude: [
          /.html$/,
          /.(js|jsx)$/,
          /.css$/,
          /.less$/,
          /.json$/,
          /.svg$/
        ],
        loader: 'url',
        query: {
          limit: 10000,
          name: 'static/media/[name].[hash:8].[ext]'
        }
      },
      {
        test: /.(js|jsx)$/,
        include: paths.appSrc,
        loader: 'babel'
      },
      {
        test: /.css$/,
        loader: ExtractTextPlugin.extract('style', 'css?importLoaders=1!postcss')
      },
      {
        test: /.less$/,
        loader: `style!css!postcss!less`
      },
      {
        test: /.json$/,
        loader: 'json'
      },
      {
        test: /.svg$/,
        loader: 'file',
        query: {
          name: 'static/media/[name].[hash:8].[ext]'
        }
      }
    ]
  },

  postcss: function () {
    return [
      autoprefixer({
        browsers: [
          '>1%',
          'last 4 versions',
          'Firefox ESR',
          'not ie < 9', // React doesn't support IE8 anyway
        ]
      }),
    ];
  },
  plugins: [
    new InterpolateHtmlPlugin({
      PUBLIC_URL: publicUrl
    }),

    new HtmlWebpackPlugin({
      inject: true,
      template: paths.appHtml,
      filename: 'index-en.html',
      chunks: ['en_US', 'common'],
      minify: {
        removeComments: true,
        collapseWhitespace: true,
        removeRedundantAttributes: true,
        useShortDoctype: true,
        removeEmptyAttributes: true,
        removeStyleLinkTypeAttributes: true,
        keepClosingSlash: true,
        minifyJS: true,
        minifyCSS: true,
        minifyURLs: true
      }
    }),
    new HtmlWebpackPlugin({
      inject: true,
      template: paths.appHtml,
      filename: 'index.html',
      chunks: ['zh_CN', 'common'],
      minify: {
        removeComments: true,
        collapseWhitespace: true,
        removeRedundantAttributes: true,
        useShortDoctype: true,
        removeEmptyAttributes: true,
        removeStyleLinkTypeAttributes: true,
        keepClosingSlash: true,
        minifyJS: true,
        minifyCSS: true,
        minifyURLs: true
      }
    }),
    new webpack.DefinePlugin(env),
    new webpack.DefinePlugin({
      "process.env": {
        NODE_ENV: JSON.stringify("production")
      }
    }),
    new webpack.optimize.OccurrenceOrderPlugin(),
    new webpack.optimize.DedupePlugin(),
    new webpack.optimize.UglifyJsPlugin({
      compress: {
        screw_ie8: true,
        warnings: false
      },
      mangle: {
        screw_ie8: true
      },
      output: {
        comments: false,
        screw_ie8: true
      }
    }),
    new ExtractTextPlugin('static/css/[name].[contenthash:8].css'),
    new ManifestPlugin({
      fileName: 'asset-manifest.json'
    })
  ],
  node: {
    fs: 'empty',
    net: 'empty',
    tls: 'empty'
  }
};

2. 开发环境配置 webpack.config.dev.js

var autoprefixer = require('autoprefixer');
var webpack = require('webpack');
var HtmlWebpackPlugin = require('html-webpack-plugin');
var CaseSensitivePathsPlugin = require('case-sensitive-paths-webpack-plugin');
var InterpolateHtmlPlugin = require('react-dev-utils/InterpolateHtmlPlugin');
var WatchMissingNodeModulesPlugin = require('react-dev-utils/WatchMissingNodeModulesPlugin');
var getClientEnvironment = require('./env');
var paths = require('./paths');
var alias = require('./alias');

var publicPath = '/';
var publicUrl = '';
var env = getClientEnvironment(publicUrl);

module.exports = {
  devtool: 'cheap-module-source-map',
  entry: {
    common: [
      require.resolve('react-dev-utils/webpackHotDevClient'),
      require.resolve('./polyfills'),
      paths.appIndexJs
    ],
    zh_CN: paths.i18n['zh-CN'],
    en_US: paths.i18n['en-US']
  },
  output: {
    path: paths.appBuild,
    pathinfo: true,
    filename: 'static/js/[name].bundle.js',
    publicPath: publicPath
  },
  resolve: {
    fallback: paths.nodePaths,
    extensions: ['.js', '.json', '.jsx', ''],
    alias
  },

  module: {
    preLoaders: [
      {
        test: /.(js|jsx)$/,
        loader: 'eslint',
        include: paths.appSrc,
      }
    ],
    loaders: [
      {
        exclude: [
          /.html$/,
          /.(js|jsx)$/,
          /.less$/,
          /.css$/,
          /.json$/,
          /.svg$/
        ],
        loader: 'url',
        query: {
          limit: 10000,
          name: 'static/media/[name].[hash:8].[ext]'
        }
      },
      {
        test: /.(js|jsx)$/,
        include: paths.appSrc,
        loader: 'babel'
      },
      {
        test: /.less$/,
        loader: `style!css!postcss!less`
      },
      {
        test: /.css$/,
        loader: 'style!css?importLoaders=1!postcss'
      },
      {
        test: /.json$/,
        loader: 'json'
      },
      {
        test: /.svg$/,
        loader: 'file',
        query: {
          name: 'static/media/[name].[hash:8].[ext]'
        }
      }
    ]
  },

  postcss: function () {
    return [
      autoprefixer({
        browsers: [
          '>1%',
          'last 4 versions',
          'Firefox ESR',
          'not ie < 9',
        ]
      }),
    ];
  },
  plugins: [
    new InterpolateHtmlPlugin({
      PUBLIC_URL: publicUrl
    }),
    new HtmlWebpackPlugin({
      inject: true,
      template: paths.appHtml,
      filename: 'index.html',
      chunks: ['zh_CN', 'common']
    }),
    new HtmlWebpackPlugin({
      inject: true,
      template: paths.appHtml,
      filename: 'index-en.html',
      chunks: ['en_US', 'common']
    }),
    new webpack.DefinePlugin(env),
    new webpack.HotModuleReplacementPlugin(),
    new CaseSensitivePathsPlugin(),
    new WatchMissingNodeModulesPlugin(paths.appNodeModules)
  ],
  node: {
    fs: 'empty',
    net: 'empty',
    tls: 'empty'
  }
};