Babel 轉換打包套件

npm install --save-dev babel-loader @babel/core
npm install @babel/preset-env --save-dev

{
  module: {
    rules: [
      {
        test: /\.m?js$/,
        exclude: /node_modules/,
        use: {
          loader: "babel-loader"
        }
      }
    ]
  }
}

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