mteacher/babel.config.js

// [["@vue/app",
//         { useBuiltIns: "entry",
//         polyfills: [
//             'es6.promise',
//             'es6.symbol'
//            ]},
//     ]],
// ["@vue/app"]
module.exports = {
  presets: [
    [
      "@vue/app",
      { useBuiltIns: "entry", polyfills: ["es6.promise", "es6.symbol"] },
    ],
  ],
  plugins: [
    [
      "import",
      {
        libraryName: "vant",
        libraryDirectory: "es",
        style: (name) => `${name}/style/less`,
      },
    ],
    "@babel/plugin-proposal-optional-chaining",
  ],
};