postcss-preset-env 自动添加css兼容性前缀

### 代码在下面 这是webpack5 （关于browserslist的相关信息点击这里）

需要安装 

postcss

postcss-loader

postcss-preset-env

 

// package.json
{
  "name": "webpack-demo",
  "version": "1.0.0",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "build": "webpack",
    "watch": "webpack --watch",
    "start": "webpack serve"
  },
  "author": "",
  "license": "ISC",
  "keywords": [],
  "description": "",
  "private": true,
  "devDependencies": {
    "clean-webpack-plugin": "^3.0.0",
    "css-loader": "^5.0.1",
    "file-loader": "^6.2.0",
    "html-loader": "^1.3.2",
    "html-webpack-plugin": "^4.5.1",
    "mini-css-extract-plugin": "^1.3.4",
    "postcss": "^8.2.4",
    "postcss-loader": "^4.1.0",
    "postcss-preset-env": "^6.7.0",
    "style-loader": "^2.0.0",
    "url-loader": "^4.1.1",
    "webpack": "^5.11.1",
    "webpack-cli": "^4.3.1",
    "webpack-dev-server": "^3.11.1"
  },
  "dependencies": {
    "lodash": "^4.17.20"
  },
  "browserslist": {
    "development": [
      "last 1 chrome version",
      "last 1 firefox version",
      "last 1 safari version"
    ],
    "production": [
      "ie > 6",
      ">1%",
      "not dead",
      "not op_mini all"
    ]
  }
}

// webpack.config.js

const path = require('path');
const webpack = require('webpack')
const HtmlWebpackPlugin = require('html-webpack-plugin');
const { CleanWebpackPlugin } = require('clean-webpack-plugin');
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
process.env.NODE_ENV = 'development'
module.exports = {
    target: process.env.NODE_ENV == 'development' ? 'web' : 'browserslist',
    // mode: "production",
    mode: "development",
    entry: {
        'js/app': './src/index.js',
    },
    // devtool: 'inline-source-map',
    devServer: {
        compress: true,
        open: false
    },
    output: {
        publicPath: '/',
        // 指定打包后输出的文件名
        filename: 'app.[contenthash:10].js',
        // 指定打包后输出的目录
        path: path.resolve(__dirname, 'dist')
    },
    resolve: {
        alias: {
            "@": path.resolve(__dirname, 'src')
        }
    },
    module: {
        rules: [
            {
                // 匹配 [.html] 文件
                test: /\.html$/,
                // 符合的文件使用以下loader进行解析
                use: ['html-loader']
            },
            {
                // 匹配 [.css] 文件
                test: /\.css$/,
                // 符合的文件使用以下loader进行解析
                use: [
                    MiniCssExtractPlugin.loader,
                    // 'style-loader',
                    'css-loader',
                    {
                        loader: "postcss-loader",
                        options: {
                            postcssOptions: {
                                plugins: [
                                    require("postcss-preset-env")(),
                                ]
                            }
                        }
                    },
                ]
            },
            {
                test: /\.(png|jpg|gif|svg)$/,
                use: [
                    {
                        loader: 'url-loader',
                        options: {
                            name: 'images/[name].[contenthash:10].[ext]',
                            limit: 1024 * 900,
                            esModule: false
                        }
                    },
                ]
            },
            {
                include: /\.(eot|svg|ttf|woff|woff2)$/,
                use: [
                    {
                        loader: "file-loader",
                        options: {
                            outputPath: "fonts"
                        }
                    }
                ]
            },
            {
                exclude: /\.(eot|svg|ttf|woff|woff2|png|jpg|gif|svg|css|html|js)$/,
                use: [
                    {
                        loader: 'file-loader',
                        options: {
                            name: '[name].[contenthash:10].[ext]',
                        }
                    }],
            },
        ]
    },
    plugins: [
        new CleanWebpackPlugin(),
        new webpack.BannerPlugin({
            banner: "bugfix2019"
        }),
        new HtmlWebpackPlugin({
            title: '王二狗',
            template: "src/index.html",
            favicon: "src/assets/images/favicon.ico"
        }),
        new MiniCssExtractPlugin(
            { filename: 'css/app.[contenthash:10].css' }
        )
    ]
};