生产模式介绍

生产模式是开发完成代码后，需要得到代码将来部署上线

这个模式下我们主要对代码进行优化，让其运行性能更好

优化从两个角度出发：

• 优化代码运行性能
• 优化代码打包速度

生产模式准备

分别准备两个不同的配置文件来存放不同的配置

1. 文件目录

├── webpack-test (项目根目录)
    ├── config (Webpack配置文件目录)
    │    ├── webpack.dev.js(开发模式配置文件)
    │    └── webpack.prod.js(生产模式配置文件)
    ├── node_modules (下载包存放目录)
    ├── src (项目源码目录，除了html其他都在src里面)
    │    └── 略
    ├── public (项目html文件)
    │    └── index.html
    ├── .eslintrc.js(Eslint配置文件)
    ├── babel.config.js(Babel配置文件)
    └── package.json (包的依赖管理配置文件)

2.修改webpack.dev.js

因为文件目录变了，所以所有绝对路径需要回退一层目录才能找到对应的文件

const path = require('path')
const ESLintWebpackPlugin = require('eslint-webpack-plugin')
const HTMLWebpackPlugin = require('html-webpack-plugin')

module.exports = {
  entry: './src/main.js',
  output: {
    path: undefined,
    filename: 'static/js/index.js',
    clean: true
  },
  module: {
    rules: [{
      test: /\.css$/,
      use: ['style-loader', 'css-loader']
    },{
      test: /\.less$/,
      use: ['style-loader', 'css-loader', 'less-loader']
    },{
      test: /\.s[ac]ss$/,
      use: ['style-loader', 'css-loader', 'sass-loader']
    },{
      test: /\.styl$/,
      use: ['style-loader', 'css-loader', 'stylus-loader']
    },{
      test: /\.(png|jpe?g|gif|webp)$/,
      type: 'asset',
      parse: {
        dataUrlCondition: {
          maxSize: 10* 1024
        }
      },
      generator: {
        filename: 'static/images/[hash:10][ext][query]'
      }
    },{
      test: /\.(ttf|woff2?|avi|mp3|mp4)$/,
      type: 'asset/resource',
      generator: {
        filename: 'static/media/[hash:10][ext][query]'
      }
    },{
      test: /\.js$/,
      exclude: 'node_module',
      loader: 'babel-loader'
    }]
  },
  loaders: [
    new ESLintWebpackPlugin({
      context: path.resolve(__dirname, '../src')
    }),
    new HTMLWebpackPlugin({
      template: path.resolve(__dirname, '../public/index.html')
    })
  ],
  devServer: {
    host: 'localhost',
    port: '8080',
    open: true
  },
  mode: 'development'
}

运行开发模式的代码

  npx webpack server --config ./config/webpack.dev.js

3. 修改webpack.prod.js

const path = require('path')
const ESLintWebpackPlugin = require('eslint-webpack-plugin')
const HTMLWebpackPlugin = require('html-webpack-plugin')

module.exports = {
  entry: './src/main.js',
  output: {
    // 需要输出
    path: path.resolve(__dirname, '../dist'),
    filename: 'static/js/index.js',
    clean: true
  },
  module: {
    rules: [{
      test: /\.css$/,
      use: ['style-loader', 'css-loader']
    },{
      test: /\.less$/,
      use: ['style-loader', 'css-loader', 'less-loader']
    },{
      test: /\.s[ac]ss$/,
      use: ['style-loader', 'css-loader', 'sass-loader']
    },{
      test: /\.styl$/,
      use: ['style-loader', 'css-loader', 'stylus-loader']
    },{
      test: /\.(png|jpe?g|gif|webp)$/,
      type: 'asset',
      parse: {
        dataUrlCondition: {
          maxSize: 10* 1024
        }
      },
      generator: {
        filename: 'static/images/[hash:10][ext][query]'
      }
    },{
      test: /\.(ttf|woff2?|avi|mp3|mp4)$/,
      type: 'asset/resource',
      generator: {
        filename: 'static/media/[hash:10][ext][query]'
      }
    },{
      test: /\.js$/,
      exclude: 'node_module',
      loader: 'babel-loader'
    }]
  },
  loaders: [
    new ESLintWebpackPlugin({
      context: path.resolve(__dirname, '../src')
    }),
    new HTMLWebpackPlugin({
      template: path.resolve(__dirname, '../public/index.html')
    })
  ],
  // 无需开发服务器
//   devServer: {
//     host: 'localhost',
//     port: '8080',
//     open: true
//   },
  mode: 'production'
}

运行生产模式需要的代码

  npx webpack --config ./config/webpack/prod.js

4. 配置运行指令

为了方便运行不同模式的指令，我们将指令定义在package.json中的scripts里面

// package.json
{
    "scripts": {
      "start": "npm run dev",
      "dev": "npx webpack server --config ./config/webpack.dev.js",
      "build": "npx webpack --config ./config/webpack.prod.js"
    }
}

以后启动指令：

• 开发模式：npm start 或 npm run dev
• 生产模式：npm run build