{
  "name": "webpac-demo",
  "version": "1.0.0",
  "description": "webpack練習(xí)",
  "main": "index.js",
  "scripts": {
    //配置開(kāi)發(fā)環(huán)境參數(shù)。注意：真實(shí)開(kāi)發(fā)中 package.json 文件中不能有注釋
    "dev": "webpack --env=development",
    //配置生產(chǎn)環(huán)境參數(shù)
    "dist": "webpack --env=production",
    "start": "webpack-dev-server --env=development"
  },
  "dependencies": {
    "font-awesome": "^4.7.0",
    "react": "^16.2.0",
    "react-dom": "^16.2.0"
  },
  "devDependencies":{
  ...
  }
}

// test.js
var args = require('minimist')(process.argv.slice(2));
console.log(args.hello);

$ node test.js --env=production
// production
$ node test.js --env=development
// development
$ node test.js --env
// true 注意：不是空字符串而是true

// webpack.config.js

const webpack = require('webpack');
//當(dāng)前項(xiàng)目的絕對(duì)路勁
const path = require('path');

// 命令行參數(shù)解析引擎
const argv = require('minimist')(process.argv.slice(2));

let env = null;

switch (argv.env) {
  case 'production':
    //生產(chǎn)環(huán)境配置文件名 
    env = 'webpack.config.prod';
    break;
  default:
    //開(kāi)發(fā)環(huán)境配置文件名 
    env = 'webpack.config.dev';

}

console.log(`當(dāng)前是 ${argv.env} 打包`);

// 這時(shí)候，我們就可以加載相應(yīng)的wabpack配置了。
module.exports = require( path.resolve( '加載的配置文件路勁'，env ) );

// 開(kāi)發(fā)環(huán)境打包配置

const path = require('path');
const webpack = require('webpack');
const base = require('./webpack.config.base')
const dfPath = require('./path')
// webpack配置合并工具
const merge =require('webpack-merge')


const RS = (...arg)=>path.resolve( __dirname , ...arg )

// 合并方式配置
let strategyMerge = merge.strategy({
  entry: 'prepend'
});

let config = {
  entry: {
    app: path.resolve(dfPath.root,'src/app.js')
  },

  output: {
    path: dfPath.dist,
    filename: '[name].bundle.js',
    publicPath: '/',
    chunkFilename: '[name].sepChunk.js'
  },
  module:{
    rules: [
      {
        test: /\.js$/,
        use:['babel-loader'],
        exclude: [
          dfPath.node_modules
        ]
      },
      {
        test:/\.css$/,
        use:[
          'style-loader',
          {
            loader:'css-loader',
            options:{
              // css模塊化，方便多人開(kāi)發(fā)
              module:true,
              // 定義模塊化css后的類(lèi)名（默認(rèn)為hash值，可讀性差）path:路勁； name：文件名； local：本地定義的className
              localIdentName: '[path][name]__[local]--[hash:base64:5]'
            },
          }
        ],
        // 排除的文件，遇到這些文件不會(huì)用當(dāng)前 loader 處理，也就不會(huì)模塊化
        exclude:[
          RS('./src/common'),         
          RS('node_modules')
        ]
      },
      {
        test:/\.css$/,
        use:['style-loader','css-loader'],
        include:[
          RS('./src/common'),         
          RS('node_modules')
        ]
        
      },      
      
      {
        test: /\.(png|jpg|jpeg|gif)$/,
        use: ['url-loader?limit=8192'],
      }
    ]
  },
  plugins:[
    // 模塊熱替換功能
    new webpack.HotModuleReplacementPlugin()
  ],
  
  // 代碼映射，方便報(bào)錯(cuò)時(shí)，找到對(duì)應(yīng)的源代碼
  devtool: 'cheap-module-eval-source-map',

  devServer:{
    // 服務(wù)器打包后，輸出的資源路勁
    publicPath:'/',
    open:true
  }
};

// 導(dǎo)出合并后的webpack配置
module.exports = strategyMerge( base , config );

// 生產(chǎn)環(huán)境配置
const webpack = require('webpack');
const base = require('./webpack.config.base')
const path = require('path');
const dfPath = require('./path');
const merge = require('webpack-merge');

// 壓縮工具
const ClosureCompilerPlugin = require('webpack-closure-compiler');
// css單獨(dú)打包插件
const extractTextWebpackPlugin = require('extract-text-webpack-plugin');

const extractCSS = new extractTextWebpackPlugin('assets/css/[name]_[contenthash:6].css');

// weback合并配置
let strategyMerge = merge.strategy({
  entry: 'replace',
  output: 'replace',
  module:{
    rules: 'replace'
  }
});

let config ={

  entry: {
    // 公共模塊拆分，這些代碼會(huì)單獨(dú)打包，一般我們會(huì)把引用的框架文件拆分出來(lái)，方便瀏覽器緩存，節(jié)省資源。
    vender:['react'],
    app: path.resolve(dfPath.root,'src/app.js')
  },
  
  output: {
    path: dfPath.dist,
    filename: 'assets/js/[name]_[chunkhash].bundle.js',
    publicPath: '/',
    chunkFilename: 'assets/js/[name].sepChunk.js',
    hashDigestLength: 6
  },

  module:{
    rules: [
      {
        test: /\.js$/,
        use:['babel-loader'],
        exclude: [
          dfPath.node_modules
        ]
      },
      /* 開(kāi)啟 css單獨(dú)打包 和 css模塊化的配置 */ 
      {
        test: /\.css$/,
        use: extractCSS.extract({
          use: [
            {
              loader: 'css-loader',
              options:{
                modules: true
              }              
            }
          ]
        })
      },     

      {
        test: /\.(png|jpg|jpeg|gif)$/,
        use: [
          {
            loader: 'url-loader',
            options:{
              limit:8192,
              name: '[name]_[hash].[ext]',
              outputPath: 'assets/img/'
            }
          }
        ],
      },
      
      {
        test: /\.(mp4|ogg|svg|ico)$/,
        use: [
          {
            loader: 'file-loader',
            options:{
              name: '[name]_[hash].[ext]',
              outputPath: 'assets/media/'
            }
          }
        ]
      },
      {
        test: /\.(woff|woff2)(\?v=\d+\.\d+\.\d+)?$/,
        use: [

          {
            loader: 'url-loader',
            options:{
              limit:10000,
              name: '[name]_[hash].[ext]',
              outputPath: 'assets/font/',
              mimetype: 'application/font-woff'
            }
          }
        ]
      },
      {
        test: /\.ttf(\?v=\d+\.\d+\.\d+)?$/,
        use: [
          {
            loader: 'url-loader',
            options:{
              limit:10000,
              name: '[name]_[hash].[ext]',
              outputPath: 'assets/font/',
              mimetype: 'application/octet-stream'
            }
          }
        ]
      },
      {
        test: /\.eot(\?v=\d+\.\d+\.\d+)?$/,
        use: [
          {
            loader: 'file-loader',
            options:{
              name: '[name]_[hash].[ext]',
              outputPath: 'assets/font/',
            }
          }
        ]
      },
      {
        test: /\.svg(\?v=\d+\.\d+\.\d+)?$/,
        use: [
          {
            loader: 'url-loader',
            options:{
              limit:10000,
              name: '[name]_[hash].[ext]',
              outputPath: 'assets/font/',
              mimetype: 'image/svg+xml'
            }
          }
        ]
      },

    ]
  },

  plugins:[
    extractCSS,
    
    // 設(shè)置 process.env（生產(chǎn)環(huán)境） 環(huán)境變量的快捷方式。
    new webpack.EnvironmentPlugin({
      NODE_ENV: 'production'
    })    
    ,new ClosureCompilerPlugin()
  ],

  devtool: 'source-map'
};

module.exports = strategyMerge(base,config);