Parcel 2 not picking up babel configuration in a yarn monorepo

[rauschie]

🐛 bug report

🎛 Configuration (.babelrc, package.json, cli command)

Currently it seems that in a yarn monorepo, parcel does not pick up neither .babelrc, nor "babel" entry of package.json, whether its located at the workspace root or subrepo root.

🤔 Expected Behavior

The linked repo should build. Babel configuration in a subrepo root should be respected, or at the very least info should be provided where to put babel configuration in a monorepo in order for it to get respected by parcel

😯 Current Behavior

In a monorepo parcel complains about absence of plugin that is defined in .babelrc, regardless of .babelrc location

💁 Possible Solution

🔦 Context

I am trying to build a subrepo using parcel. Subrepo uses private class fields.

💻 Code Sample

the repo used to demonstrate the bug supposedly fixed in #4132 still does not build neither with beta.2 nor with nightly.639

🌍 Your Environment

Software	Version(s)
Parcel
Node
npm/Yarn
Operating System

[Fr33maan]

I actually HAD TO add a package-lock.json (even an empty one works) in the subrepo to have the subrepo babel.config.json to be used by parcel.
I'm using a monorepo structure with lerna.

You can see in the doc that a package.json is not enough for parcel to consider a directory as a project directory, which is pretty confusing I think.

[rauschie]

You can see in the doc that a package.json is not enough for parcel to consider a directory as a project directory, which is pretty confusing I think.

Well That's cute. Dropping an empty package-lock.json in the subrepo did indeed solve the problem, a million thanks for the workaround!

[mischnic]

Adding package-lock.json files is not the correct solution.

Parcel just uses Babel's config resolution here, so this section applies: https://babeljs.io/docs/en/config-files#monorepos (so the "usual" approach of .babelrc's doesn't work in monorepos)

[mischnic]

As described in the linked docs, you need to add a babel.config.json file in the root containing:

{ "babelrcRoots": ["app1", "app2"] }