Support ESM

[jasonkuhrt]

Verify canary release

• I verified that the issue exists in the latest Next.js canary release

Provide environment information

Operating System:
      Platform: darwin
      Arch: arm64
      Version: Darwin Kernel Version 22.3.0: Mon Jan 30 20:38:37 PST 2023; root:xnu-8792.81.3~2/RELEASE_ARM64_T6000
    Binaries:
      Node: 16.19.0
      npm: 8.19.3
      Yarn: 1.22.19
      pnpm: 7.11.0
    Relevant packages:
      next: 13.2.4
      eslint-config-next: 13.2.4
      react: 18.2.0
      react-dom: 18.2.0

Which area(s) of Next.js are affected? (leave empty if unsure)

TypeScript

Link to the code that reproduces this issue

N/A

To Reproduce

Make app be ESM:

1. "type": "module", in package.json
2. "module": "NodeNext", in tsconfig.json
3. "moduleResolution": "nodenext", in tsconfig.json

Watch imports from e.g. next/head fail.

Describe the Bug

Next.js is not an ESM package.

Expected Behavior

Next.js should be an ESM package.

Which browser are you using? (if relevant)

N/A

How are you deploying your application? (if relevant)

N/A

_NEXT-2389

[samcx]

Did you update your next.config.js to next.config.cjs?

[jasonkuhrt]

@samcx No, but I'm not sure how that is relevant. Also using CJS is a step in the wrong direction too. In the source code, one can see exports are not used in the package manifest. That is a problem.

[balazsorban44]

I can confirm this. here is a repro: https://github.com/balazsorban44/next-submodules-ts-nodenext

I took at stab at it in #61525 but as expected, it broke a lot of things. I'll see how we can tackle this more incrementally.

[karlhorky]

@balazsorban44 @samcx is this a duplicate of this other issue over here?

• [NEXT-779] next/* - Typescript cannot find module when moduleResolution=nodenext and type=module #46078

(the other issue has more upvotes and also a different PR #50357 from @lucgagan which aims to resolve it)

If yes, then these internal Linear tracking numbers are also duplicates:

• NEXT-2389 (this current issue)
• NEXT-779 (connected to issue 46078)

[samcx]

@karlhorky That seems so, let's close this one and keep the older one.

[github-actions]

This closed issue has been automatically locked because it had no new activity for 2 weeks. If you are running into a similar issue, please create a new issue with the steps to reproduce. Thank you.