webpack 之，12 生产环境

未测试,只是记录下来而已

const {resolve} = require('path')
const MiniCssExtractPlugin = require('mini-css-extract-plugin')
const OptimizeCssAssetsWebpackPlugin = require('optimize-css-assets-webpack-plugin')


/* 
  关于js
  正常来讲,一个文件只能被一个loader处理 
  当一个文件要被多个loader处理,那么一定要指定loader执行的先后顺序
     先执行eslint 在 执行 babel
*/

//定义nodejs环境变量:决定使用browserslist的哪个环境
process.env.NODE_ENV = 'production'

const commonCssLoader = [
  MiniCssExtractPlugin.loader,
  'css-loader',
  {
    //还需要在package.js中定义browserslist
    loader:'post-loader'
  }
]

module.exports ={
  entry:'./src/js/index.js',
  output:{
    filename:'js/built.js',
    path:resolve(__dirname,'build')
  },
  module:{
    rules:[
      {
        test:/\.css$/,
        //use 从下到上执行
        use:[
         ...commonCssLoader
        ]
      },
      {
        test:/\.less$/,
        use:[
          ...commonCssLoader,
          'less-loader'
        ]
      },
      {
        /* 在package.json中eslintConfig   -->airbnb*/
        test:/\.js$/,
        exclude:/node_modules/,
        // 优先执行
        enforce:'pre',
        loader:'eslint-loader',
        options:{
          fix:true
        }
      },
      {
        test:/\.js$/,
        exclude:/node_modules/,
        loader:'babel-loader',
        options:{
          presets:[
            '@babel/preset-env',
            {
              userBuiltIns:'usage',
              corejs:{version:3},
              targets:{
                chrome:'60',
                firefox:'50'
              }
            }
          ]
        }
      },
      {
        test:/\.(jpg|png|gif)/$,
        loader:'url-loader',
        options:{
          limit:8*1024,
          name:'[hash:10].[ext]',
          outputPath:'imgs',
          esModule:false
        }
      },
      {
        test:/\.html$/,
        loader:'html-loader'
      },
      {
        exclude:/.(js|css|html|jpg|png|gif)/,
        loader:'file-loader',
        options:{
          outputPath
        }
      }
    ]
  },
  plugins:[
    new HtmlWebpackPlugin({
      template:'./src/index.html',
      minify:{
        collapseWhitespace:true,
        removeComments:true
      }
    }),
    new MiniCssExtractPlugin({
      filename:'css/built.css'
    }),
    new OptimizeCssAssetsWebpackPlugin()
  ],
  mode:'development'
}

{
  "name": "12webpackproduction",
  "version": "1.0.0",
  "description": "",
  "main": "postcss.config.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "css-loader": "^5.2.4",
    "file-loader": "^6.2.0",
    "html-webpack-plugin": "^5.3.1",
    "mini-css-extract-plugin": "^1.5.0",
    "postcss-loader": "^5.2.0",
    "postcss-preset-env": "^6.7.0",
    "style-loader": "^2.0.0",
    "url-loader": "^4.1.1"
  },
  "browserslist": {
    "development": [
      "last 1 chrome version",
      "last 1 firefox version",
      "last 1 safari version"
    ],
    "production": [
      ">0.2%",
      "not dead",
      "not op_mini all"
    ],
    "eslintConfig": {
      "extends": "airbnb-base"
    }
  }
}