Hey 吕立青, Great question. We need to use @babel/preset-env which transforms syntax. We need to use @babel/transform-runtime to avoid duplicate code, and config core-js: 3 to polyfill.

babel-plugin-transform-runtime automatically injects Regenerator where generators or async/await are used.

So, installing babel/runtime and @babel/plugin-transform-runtime will solve your problem.

So, what you can do is,

yarn add @babel/plugin-transform-runtime --dev
yarn add @babel/runtime

and in .babelrc, you can add this plugin.

"plugins": [
    ["@babel/plugin-transform-runtime",
      {
        "regenerator": true
      }
    ]
  ]

By default regenerator is true