Correct way to add babel plugins in monorepo

[quangta93]

I am using Parcel 1.12.4 to build an application that uses some large libraries including rxjs and material-ui. The build & package time for development is painfully slow (sometimes up to 10-15 minutes for initial build and 3-4s for subsequent iterations). Since Parcel doesn't support tree-shaking on development, I am following this guide in order to minimize the bundle size.

Unfortunately, babel config seems to be ignored. The same config works great with Parcel 2 but I can't upgrade because another library I am using threads has issue with it.

I know that in Parcel 1, custom babel configs are merged with the default one. Could someone please give me a working example of how custom babel configs should look?

Here's my current configuration:

// .babelrc
{
  "presets": ["@babel/preset-env", "@babel/preset-typescript"],
  "plugins":  [
[
    "babel-plugin-import",
    {
      "libraryName`': "@material-ui/core",
      // Use "'libraryDirectory': ''," if your bundler does not support ES modules
      "libraryDirectory": "esm",
      "camel2DashComponentName": false
    },
    "core",
  ],
  [
    "babel-plugin-import",
    {
      "libraryName": "@material-ui/icons",
      // Use "'libraryDirectory': ''," if your bundler does not support ES modules
      "libraryDirectory": "esm",
      "camel2DashComponentName": false
    },
    "icons",
  ]
]
}

[quangta93]

I've limited this issue to babel config being ignored when Parcel has to work in a monorepo (I'm using lerna). I've setup a repo (https://github.com/quangta93/lerna-parcel) based on recommendation from babel config guide for monorepo

Once running foo app, you should see Uncaught ReferenceError: regeneratorRuntime is not defined because async/await is not supported even though "targets": "last 2 Chrome versions" should fix that. If I add "browserslist": ["last 2 Chrome versions"] inside the app's package.json, the issue goes away.

@mischnic @devongovett any suggestions please?

[quangta93]

The reason I need .babelrc.json to work is because I need to make the above plugins work. I can't simply use browserslist config.

[quangta93]

nvm the above issue has been resolved by using [email protected] with the exact babel config approach. I am guessing we want to move forward with v2 in the future so this won't be in high priority.