vue项目配置可选调用链

cnpm i --save-dev @babel/plugin-proposal-optional-chaining

{
  "plugins": ["@babel/plugin-proposal-optional-chaining"]
}

module.exports = {
  presets: [
    "@babel/preset-env",
    ['@vue/app',
      { useBuiltIns: 'entry' }]
  ],
  "plugins": ["@babel/plugin-transform-runtime", "@babel/plugin-proposal-optional-chaining",]
}