webpack.config.js

const path = require("path");
const HtmlWebpackPlugin = require("html-webpack-plugin");
module.exports = {
  mode: "development",
  //入口文件
  entry: "./src/index.ts",
  //出口文件
  output: {
    path: path.resolve(__dirname, "dist"),
    filename: "bundle.js",
    //告诉webpack不是用箭头函数,和const， ie 老版本不兼容const和arrow function
    environment: {
      arrowFunction: false,
      const: false,
    },
  },
  //使用的插件
  plugins: [
    new HtmlWebpackPlugin({
      template: "./src/index.html",
    }),
  ],
  module: {
    rules: [
      {
        //
        test: /\.ts$/,
        //使用的loader(从下向上执行)
        use: [
          //配置babel
          {
            //指定加载器
            loader: "babel-loader",
            //设置babel
            options: {
              //设置定义环境
              presets: [
                [
                  //环境插件
                  "@babel/preset-env",
                  //配置文件
                  {
                    //兼容浏览器版本
                    targets: {
                      chrome: "58",
                      ie: "11",
                    },
                    //指定corejs的版本
                    corejs: "3",
                    //使用corejs的方式 usage按需加载
                    useBuiltIns: "usage",
                  },
                ],
              ],
            },
          },

          "ts-loader",
        ],
        exclude: /node_modules/,
      },
      {
        test: /\.less$/,
        use: [
          "style-loader",
          "css-loader",
          //引入postcss(解决不同浏览器对css的兼容性问题)
          {
            loader: "postcss-loader",
            options: {
              postcssOptions: {
                plugins: [
                  [
                    "postcss-preset-env",
                    {
                      browsers: "last 3 versions",
                    },
                  ],
                ],
              },
            },
          },
          "less-loader", //将less style编译成css
        ],
        exclude: /node_modules/,
      },
    ],
  },
  devServer: {
    contentBase: "./dist",
    //是否实时监听
    inline: true,
  },
  //设置引用的模块
  resolve: {
    extensions: [".ts", ".js"],
  },
};