purgecss-webpack-plugin

purgecss-webpack-plugin 用于去除无用的样式

准备

---

安装purgecss-webpack-plugin、mini-css-extract-plugin、css-loader、glob 依赖

yarn add purgecss-webpack-plugin mini-css-extract-plugin css-loader glob -D

配置

---

1. webpack.config.js 配置 purgecss-webpack-plugin 与 mini-css-extract-plugin

const Path = require("path");
const glob = require("glob");
const HtmlWebpackPlugin = require('html-webpack-plugin');
const PurgecssPlugin = require("purgecss-webpack-plugin");
const MiniCssExtractPlugin = require("mini-css-extract-plugin");

function toUnitPath(path){
  return path.replace(/\\/g,'/');
}
const PATHS = {
  src: toUnitPath(Path.resolve(__dirname, "src")),
};

module.exports = {
  entry: Path.resolve(__dirname, "src", "index.js"),
  mode: "development",
  output: {
    filename: "index.js",
    path: Path.resolve(__dirname, "build"),
  },
  module: {
    rules: [
      {
        test: /\.css$/,
        include: Path.resolve(__dirname, "src"),
        exclude: /node_modules/,
        use: [
          {
            loader: MiniCssExtractPlugin.loader,
          },
          "css-loader",
        ],
      },
    ],
  },
  plugins: [
    new HtmlWebpackPlugin({
      template:Path.resolve(__dirname,'index.html')
    }),
    new MiniCssExtractPlugin({
      filename: "[name].css",
    }),
    new PurgecssPlugin({
      paths: glob.sync(`${PATHS.src}/**/*`, { nodir: true }),
    }),
  ],
};

2. 编写index.css: 尽量多编写一些无用的样式

.cssDom{
  width:100px;
  height:100px;
  background-color: aqua;
}

.lessDom{
  width:100px;
  height:100px;
  background-color: aqua;
}

.scssDom{
  width:100px;
  height:100px;
  background-color: aqua;
}

3. 编写index.js入口文件: 使用index.css其中的一个类名

import './index.css'

const cssDom = document.createElement('div');
cssDom.classList.add('cssDom');
document.body.append(cssDom);

4. 查看output输出目录: 此时index.css 打包文件中只有index.js 中使用到的类名

/*!******************************************************************!*\
!*** css ../node_modules/css-loader/dist/cjs.js!./src/index.css ***!
\******************************************************************/
.cssDom{
  width:100px;
  height:100px;
  background-color: aqua;
}