Build fails with experimental ESM loader

[kherock]

What version of Next.js are you using?

12.0.3

What version of Node.js are you using?

16.13.0

What browser are you using?

N/A

What operating system are you using?

macOS

How are you deploying your application?

N/A

Describe the Bug

When using Next.js with Yarn 3's experimental ESM loader enabled, builds will hang for a while and eventually fail. The build process's dependence on jest-worker is causing builds to fail when --experimental-loader is passed as a Node runtime argument. There isn't much that Next.js can do to fix this, but I just wanted to bring attention to this issue since PnP users will otherwise have to explicitly opt-out of ESM support starting in Yarn v3.2 and Next.js 12.

I've opened an issue on jest-worker tracked here: jestjs/jest#12060

I want to make it clear that this is not a Yarn/PnP bug. This is probably a Node.js quirk with how they've implemented their ESM loader hook.

Expected Behavior

The app should build a starter project without errors with Yarn 3 while PnP is enabled.

To Reproduce

A reproduction repo is available here: https://github.com/kherock/jest-worker-spawn-bug

Please check out the README there for more context.

$ yarn install
$ yarn build-with-loader
node:internal/validators:119
    throw new ERR_INVALID_ARG_TYPE(name, 'string', value);
    ^

TypeError [ERR_INVALID_ARG_TYPE]: The "id" argument must be of type string. Received null
    at new NodeError (node:internal/errors:371:5)
    at validateString (node:internal/validators:119:11)
    at Module.require (node:internal/modules/cjs/loader:998:3)
    at require (node:internal/modules/cjs/helpers:102:18)
    at execMethod (/Users/herockk/Workspaces/jest-worker-spawn-bug/node_modules/jest-worker/build/workers/processChild.js:107:16)
    at process.messageListener (/Users/herockk/Workspaces/jest-worker-spawn-bug/node_modules/jest-worker/build/workers/processChild.js:39:7)
    at process.emit (node:events:390:28)
    at emit (node:internal/child_process:917:12)
    at processTicksAndRejections (node:internal/process/task_queues:84:21) {
  code: 'ERR_INVALID_ARG_TYPE'
}

[kherock]

I've just realized that we can use worker_threads as a workaround, it doesn't have this timing issue. Next.js already supports passing this to jest-worker with experimental: { workerThreads: true } in next.config.js. Worker threads are available in all maintained Node versions:

https://nodejs.org/docs/latest-v12.x/api/worker_threads.html

Jest also implements a fallback in case the current environment doesn't support them.

[sidhuko]

Maybe a FAQ, I believe it should work as normal if you set pnpEnableEsmLoader: false in your .yarnrc.yml file.

[kherock]

Maybe a FAQ, I believe it should work as normal if you set pnpEnableEsmLoader: false in your .yarnrc.yml file.

I depend on ESM packages, this isn't an option for me. However this issue is fixed for me with Node 16.14, so I'm going to close this.

[github-actions]

This closed issue has been automatically locked because it had no new activity for a month. If you are running into a similar issue, please create a new issue with the steps to reproduce. Thank you.