webpack学习笔记

一、学习webpack

1. webpack基本环境

npm init -y
cnpm i webpack webpack-cli -D
package.json下增加打包脚本

"scripts": {
    "build": "webpack"
  },

npm run build执行打包， webpack默认是执行src/index.js，然后生成到dist目录, 相当于如下的配置文件webpack.config.js

const path = require('path')

module.exports = {
  entry: {
    main: './src/index.js'
  },
  output: {
    filename: 'main.js',
    path: path.resolve(__dirname, 'dist')
  }
}

webpack默认会读取根目录下的webpack.config.js,默认的模式是production会启用压缩，增加脚本

"scripts": {
    "dev": "webpack --mode=development",
    "build": "webpack"
  },

2. webpack打包样式

index.css

* { margin: 0; padding: 0;}
body {
  background-color: red;
}

index.js

import './index.css'

console.log('webpack learning')

要打包样式需要用到 style-loader和css-loader

cnpm i style-loader css-loader -D
配置 webpack 的module节点

const path = require('path')

module.exports = {
  entry: {
    main: './src/index.js'
  },
  output: {
    filename: 'bundle.js',
    path: path.resolve(__dirname, 'dist')
  },
  module: {
    rules: [
      { test: /\.css$/, use: ['style-loader','css-loader']}
    ]
  }
}

3. `html-webpack-plugin`插件

cnpm i html-webpack-plugin -D
配置webpack

const HtmlWebpackPlugin = require('html-webpack-plugin')

  plugins: [
    new HtmlWebpackPlugin({
      title: 'webpack + react学习',
      template: 'index.html'
    })
  ]

index.html模板文件




  
  
  
  <%= htmlWebpackPlugin.options.title %>

4. 样式文件打包到单独的文件中

cnpm i mini-css-extract-plugin -D
配置

const MiniCssExtractPlugin = require('mini-css-extract-plugin')

module: {
    rules: [
      { test: /\.css$/, use: [{
        loader: MiniCssExtractPlugin.loader
      },'css-loader']}
    ]
  },
  plugins: [
    new HtmlWebpackPlugin({
      title: 'webpack + react学习',
      template: 'index.html'
    }),
    new MiniCssExtractPlugin({
      filename: '[name].css',
      chunkFilename: '[id].css', // 这里的id就是 entry 对象的 main
      ignoreOrder: false, // Enable to remove warnings about conflicting order
    })
  ]

5. 区别开发环境和生产环境

cnpm i cross-env -D
改写package.json的执行脚本

"scripts": {
    "dev": "cross-env NODE_ENV=development webpack --mode=development",
    "build": "cross-env NODE_ENV=production webpack"
  },

改写 mini-css-extract-plugin的配置在开发环境下启用 hmr(hot module replacement)

const devMode = process.env.NODE_ENV !== 'production'
const MiniCssExtractPlugin = require('mini-css-extract-plugin')

module: {
  rules: [
    { test: /\.css$/, use: [{
      loader: MiniCssExtractPlugin.loader,
      options: {
        hmr: process.env.NODE_ENV === 'development'
      }
    },'css-loader']}
  ]
},
plugins: [
  new HtmlWebpackPlugin({
    title: 'webpack + react学习',
    template: 'index.html'
  }),
  new MiniCssExtractPlugin({
    filename: devMode ? '[name].css' : '[name].[hash].css',
    chunkFilename: devMode ? '[id].css' : '[id].[hash].css', // 这里的id就是 entry 对象的 main,此选项决定了非入口(non-entry) chunk 文件的名称。
    ignoreOrder: false, // Enable to remove warnings about conflicting order
  })
]

6. `webpack-dev-server`

cnpm i webpack-dev-server -D
webpack.config.js配置文件增加devServer配置节

devServer: {
  contentBase: './dist',
  // host: '0.0.0.0',
  port: 3000,
  open: true
},

修改package.json中的启动脚本

"scripts": {
    "dev": "cross-env NODE_ENV=development webpack-dev-server --mode=development",
    "build": "cross-env NODE_ENV=production webpack"
  },

7. 热模块替换

首先在devServer配置节启用热模块替换

const webpack = require('webpack')


devServer: {
  contentBase: './dist',
  // host: '0.0.0.0',
  port: 3000,
  hot: true, // 启用热模块替换
  open: true
},
plugins: [
  new webpack.NamedModulesPlugin(),
  new webpack.HotModuleReplacementPlugin()
]

将 css的打包修改成开发时使用 style-loader, 生产环境使用mini-css-extract-plugin

module: {
  rules: [
    { test: /\.css$/, use: [
      devMode ? 'style-loader' :
      {
      loader: MiniCssExtractPlugin.loader,
      options: {
        hmr: process.env.NODE_ENV === 'development'
      }
    },'css-loader']}
  ]
},

8. `webpack`的`devtool`

可以参考： https://segmentfault.com/a/1190000008315937

开发环境下一般配置成： devtool: 'cheap-module-source-map',
启用css-loader的sourceMap

module: {
  rules: [
    { test: /\.css$/, use: [
      devMode ? 'style-loader' :
      {
        loader: MiniCssExtractPlugin.loader,
        options: {
          hmr: process.env.NODE_ENV === 'development'
        }
      }, {
        loader: 'css-loader',
        options: { sourceMap: true }
    }]}
  ]
},

几个关键字意义

eval：使用eval包裹模块代码
source-map：产生.map文件
cheap：不包含列信息（关于列信息的解释下面会有详细介绍)也不包含loader的sourcemap
module：包含loader的sourcemap（比如jsx to js ，babel的sourcemap）
inline：将.map作为DataURI嵌入，不单独生成.map文件（这个配置项比较少见）

9. 给样式加浏览器厂商前缀

安装 cnpm i postcss-loader autoprefixer -D
配置

module: {
  rules: [
    { test: /\.css$/, use: [
      devMode ? 'style-loader' :
      {
        loader: MiniCssExtractPlugin.loader,
        options: {
          hmr: process.env.NODE_ENV === 'development'
        }
      }, {
        loader: 'css-loader',
        options: { sourceMap: true, importLoaders: 1 }
    }, "postcss-loader"]}
  ]
},

注意上面的css-loader增加了importLoaders: 1选项，该选项表示的是在交给css-loader处理前的处理loader数量，默认值是0,上面配置了postcss-loader，所以改成1

添加 postcss.config.js

module.exports = {
  plugins: [
    require('autoprefixer')
  ]
}

10. 清理dist目录

cnpm i clean-webpack-plugin -D
使用

const { CleanWebpackPlugin } = require('clean-webpack-plugin')

plugins: [
    new CleanWebpackPlugin(),
    ...
]

11. 处理图片资源

cnpm i file-loader url-loader -D
配置webconfig.js

module: {
  rules: [
    { test: /\.css$/, use: [
      devMode ? 'style-loader' :
      {
        loader: MiniCssExtractPlugin.loader,
        options: {
          hmr: process.env.NODE_ENV === 'development',
          publicPath: '../'
        }
      }, {
        loader: 'css-loader',
        options: { sourceMap: true, importLoaders: 1 }
      }, "postcss-loader"]
    },
    {
      test: /\.(png|jpg|gif)$/i,
      use: [
        {
          loader: 'url-loader',
          options: {
            limit: 1024 * 500, // 500KB以下会被转成base64
            name: 'images/[name].[hash:8].[ext]',
          },
        },
      ],
    },
  ]
},
plugins: [
  new MiniCssExtractPlugin({
    filename: devMode ? 'css/[name].css' : 'css/[name].[hash].css',
    chunkFilename: devMode ? 'css/[id].css' : 'css/[id].[hash].css', // 这里的id就是 entry 对象的 main,此选项决定了非入口(non-entry) chunk 文件的名称。
    ignoreOrder: false, // Enable to remove warnings about conflicting order
  })
]

上面有个路径问题需要特别注意

MiniCssExtractPlugin 的filename增加了css/,也就是将提取的css都放到 css目录
图片资源放置到 images目录，所以url-loader也给name增加了 images/
因为样式都被放到了css目录，要相应的给MiniCssExtractPlugin.loader 增加 publicPath: '../'

12. 字体文件

cnpm i file-loader -D
配置

module: {
  rules: [
    {
      test: /\.(woff|woff2|eot|ttf|otf)$/i,
      use: [
        {
          loader: 'file-loader',
          options: {
            name: 'fonts/[name].[hash:8].[ext]'
          }
        }
      ]
    }
  ]
}

13. 使用babel

cnpm install -D babel-loader @babel/core @babel/preset-env
根目录下增加babel的配置文件.babelrc

{
  "presets": ["@babel/preset-env"]
}

修改webpack.config.js启用babel-loader

output: {
  filename: 'js/bundle.js', // 将js都保存到js目录
  path: path.resolve(__dirname, 'dist')
},
module: {
  rules: [
    { test: /\.js$/, exclude: /node_modules/, loader: "babel-loader" }
  ]
}

14. 完整的`webpack.config.js`

webpack.config.js

const path = require('path')
const devMode = process.env.NODE_ENV !== 'production'

const HtmlWebpackPlugin = require('html-webpack-plugin')
const MiniCssExtractPlugin = require('mini-css-extract-plugin')
const webpack = require('webpack')
const { CleanWebpackPlugin } = require('clean-webpack-plugin')

module.exports = {
  entry: {
    main: './src/index.js'
  },
  output: {
    filename: 'js/bundle.js', // 将js都保存到js目录
    path: path.resolve(__dirname, 'dist')
  },
  devtool: 'cheap-module-source-map',
  devServer: {
    contentBase: './dist',
    // host: '0.0.0.0',
    port: 3000,
    hot: true, // 启用热模块替换
    open: true
  },
  module: {
    rules: [
      { test: /\.css$/, use: [
        devMode ? 'style-loader' :
        {
          loader: MiniCssExtractPlugin.loader,
          options: {
            hmr: process.env.NODE_ENV === 'development',
            publicPath: '../'
          }
        }, {
          loader: 'css-loader',
          options: { sourceMap: true, importLoaders: 1 }
        }, "postcss-loader"]
      },
      {
        test: /\.(png|jpg|gif)$/i,
        use: [
          {
            loader: 'url-loader',
            options: {
              limit: 1024 * 500, // 500KB以下会被转成base64
              name: 'images/[name].[hash:8].[ext]',
            },
          },
        ],
      },
      {
        test: /\.(woff|woff2|eot|ttf|otf)$/i,
        use: [
          {
            loader: 'file-loader',
            options: {
              name: 'fonts/[name].[hash:8].[ext]'
            }
          }
        ]
      },
      { test: /\.js$/, exclude: /node_modules/, loader: "babel-loader" }
    ]
  },
  plugins: [
    new CleanWebpackPlugin(),
    new HtmlWebpackPlugin({
      title: 'webpack + react学习',
      template: 'index.html'
    }),
    new MiniCssExtractPlugin({
      filename: devMode ? 'css/[name].css' : 'css/[name].[hash].css',
      chunkFilename: devMode ? 'css/[id].css' : 'css/[id].[hash].css', // 这里的id就是 entry 对象的 main,此选项决定了非入口(non-entry) chunk 文件的名称。
      ignoreOrder: false, // Enable to remove warnings about conflicting order
    }),
    new webpack.NamedModulesPlugin(),
    new webpack.HotModuleReplacementPlugin()
  ]
}

package.json中的脚本

"scripts": {
  "dev": "cross-env NODE_ENV=development webpack-dev-server --mode=development",
  "devTest": "cross-env NODE_ENV=development webpack --mode=development",
  "build": "cross-env NODE_ENV=production webpack"
},

15. 将开发和生产环境的公共配置抽离出来

因为开发和生产的配置有些是共用的配置，有些是不同的配置，如: 开发时使用style-loader方便hmr,不需要mini-css-extract-plugin,有devServer配置

而生产环境是不需要热模块替换的(hot module replacement)

建立build文件夹
cnpm i webpack-merge -D
build/webpack.common.js

const path = require('path')
const HtmlWebpackPlugin = require('html-webpack-plugin')
const { CleanWebpackPlugin } = require('clean-webpack-plugin')

module.exports = {
  entry: {
    main: path.resolve(__dirname, '../src/index.js')
  },
  output: {
    filename: 'js/bundle.js', // 将js都保存到js目录
    path: path.resolve(__dirname, '../dist')
  },
  module: {
    rules: [
      {
        test: /\.(png|jpg|gif)$/i,
        use: [
          {
            loader: 'url-loader',
            options: {
              limit: 1024 * 500, // 500KB以下会被转成base64
              name: 'images/[name].[hash:8].[ext]',
            },
          },
        ],
      },
      {
        test: /\.(woff|woff2|eot|ttf|otf)$/i,
        use: [
          {
            loader: 'file-loader',
            options: {
              name: 'fonts/[name].[hash:8].[ext]'
            }
          }
        ]
      },
      { test: /\.js$/, exclude: /node_modules/, loader: "babel-loader" }
    ]
  },
  plugins: [
    new CleanWebpackPlugin(),
    new HtmlWebpackPlugin({
      title: 'webpack + react学习',
      template: 'index.html'
    })
  ]
}

build/webpack.dev.js

const merge = require('webpack-merge')
const webpack = require('webpack')
const common = require('./webpack.common')

module.exports = merge(common, {
  mode: 'development',
  devtool: 'cheap-module-source-map',
  devServer: {
    contentBase: '../dist',
    // host: '0.0.0.0',
    port: 3000,
    hot: true, // 启用热模块替换
    open: true
  },
  module: {
    rules: [
      { test: /\.css$/, use: [
        'style-loader', 
        {
          loader: 'css-loader',
          options: { sourceMap: true, importLoaders: 1 }
        }, 
        'postcss-loader']
      },
    ]
  },
  plugins: [
    new webpack.NamedModulesPlugin(),
    new webpack.HotModuleReplacementPlugin()
  ]
})

build/webpack.prod.js

const merge = require('webpack-merge')
const MiniCssExtractPlugin = require('mini-css-extract-plugin')
const common = require('./webpack.common')

module.exports = merge(common, {
  mode: 'production',
  devtool: 'source-map',
  module: {
    rules: [
      { test: /\.css$/, use: [
        {
          loader: MiniCssExtractPlugin.loader,
          options: {
            publicPath: '../'
          }
        }, 
        {
          loader: 'css-loader',
          options: { sourceMap: true, importLoaders: 1 }
        }, 
        'postcss-loader']
      },
    ]
  },
  plugins: [
    new MiniCssExtractPlugin({
      filename: 'css/[name].[hash].css',
      chunkFilename: 'css/[id].[hash].css', // 这里的id就是 entry 对象的 main,此选项决定了非入口(non-entry) chunk 文件的名称。
      ignoreOrder: false, // Enable to remove warnings about conflicting order
    })
  ]
})

最后修改package.json中的脚本

"scripts": {
  "dev": "cross-env NODE_ENV=development webpack-dev-server --config build/webpack.dev.js",
  "devTest": "cross-env NODE_ENV=development webpack --config build/webpack.dev.js",
  "build": "cross-env NODE_ENV=production webpack --config build/webpack.prod.js"
},

遗留配置：

使用 scss、stylus等css预处理器
treeshaking 配置
公共模块的打包配置（多页面需要重点考虑，使用默认也可以）

webpack4配置记录

webpack学习笔记

一、学习webpack

1. webpack基本环境

2. webpack打包样式

3. `html-webpack-plugin`插件

4. 样式文件打包到单独的文件中

5. 区别开发环境和生产环境

6. `webpack-dev-server`

7. 热模块替换

8. `webpack`的`devtool`

9. 给样式加浏览器厂商前缀

10. 清理dist目录

11. 处理图片资源

12. 字体文件

13. 使用babel

14. 完整的`webpack.config.js`

15. 将开发和生产环境的公共配置抽离出来

你可能感兴趣的:(webpack4配置记录)

webpack4配置记录

webpack学习笔记

一、 学习webpack

1. webpack基本环境

2. webpack打包样式

3. html-webpack-plugin插件

4. 样式文件打包到单独的文件中

5. 区别开发环境和生产环境

6. webpack-dev-server

7. 热模块替换

8. webpack的devtool

9. 给样式加浏览器厂商前缀

10. 清理dist目录

11. 处理图片资源

12. 字体文件

13. 使用babel

14. 完整的webpack.config.js

15. 将开发和生产环境的公共配置抽离出来

你可能感兴趣的:(webpack4配置记录)

一、学习webpack

3. `html-webpack-plugin`插件

6. `webpack-dev-server`

8. `webpack`的`devtool`

14. 完整的`webpack.config.js`