Revisit .babelrc.js

[XhmikosR]

Not sure what was the reason behind using @babel/plugin-proposal-object-rest-spread; spread seem to be transpiled even without the extra plugin.

Also, exclude: ['transform-typeof-symbol'] does not seem to apply in our codebase.

Any hints welcome.

[razh]

• @babel/plugin-proposal-object-rest-spread

  This is now enabled by default because it's a part of ES2018.

  Archive syntax plugins enabled by default babel/babel#10820

• @babel/plugin-transform-typeof-symbol

  This does nothing if loose: true in the @babel/preset-env options:

  [preset-env] Exclude transform-typeof-symbol with loose option. babel/babel#6831

[XhmikosR]

Thanks for the reply!

It doesn't seem that the transpiled spread code is 100% the same though. It seems without @babel/plugin-proposal-object-rest-spread in plugins, babel is extending Object.assign. https://babeljs.io/docs/en/babel-plugin-proposal-object-rest-spread#loose

Not sure if there is any issue.

EDIT: here's what seems to be identical to what we have

1. remove @babel/plugin-proposal-object-rest-spread from package.json devDependencies since it's included in @babel/preset-env
2. use this config:

module.exports = {
  presets: [
    [
      '@babel/preset-env',
      {
        loose: true,
        modules: false
      }
    ]
  ],
  plugins: [
    '@babel/plugin-proposal-object-rest-spread'
  ]
}