babel-loader配置

1、npm i @babel/core、@babel/preset-env、@babel/runtime、@babel/plugin-transform-runtime、@babel/plugin-proposal-class-properties、@babel/preset-react -D

2、然后在.babelrc文件中添加{"presets":["@babel/preset-env","@babel/preset-react"], "plugins":["@babel/transform-runtime","@babel/plugin-proposal-class-properties"]}

3、在webpackconfig.js文件中添加

module: {

        rules: [

            {

              test: /\.js$/,

              exclude: /(node_modules|bower_components)/,

              use: {

                loader: 'babel-loader',

                options: {

                  presets: ['@babel/preset-env']

                }

              }

            }

          ]

    }

4、npm run dev 大功告成啦