_document.js does not work for React.JS v18

[okisdev]

Verify canary release

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

Provide environment information

Operating System:
      Platform: darwin
      Arch: arm64
      Version: Darwin Kernel Version 21.4.0: Mon Feb 21 20:36:53 PST 2022; root:xnu-8020.101.4~2/RELEASE_ARM64_T8101
    Binaries:
      Node: 17.8.0
      npm: 8.5.5
      Yarn: 1.22.18
      pnpm: N/A
    Relevant packages:
      next: 12.1.2
      react: 18.0.0
      react-dom: 18.0.0

Describe the Bug

_document.js does not work for React.JS v18

Expected Behavior

_document.js and components such as next/head should work for React.JS v18

To Reproduce

create a basic next.js project and create a _document.js file in /pages.

[SukkaW]

Have you tried react@18 with next@12.1.1?

I have run into a similar issue, and downgrading to next@12.1.1 the issue is gone. I am still comparing the changes to see which change might cause the issue.

---

Update

The custom _document.js doesn't work on 12.1.2-canary.0, too. So the change that causes the issue is between 12.1.1 and 12.1.2-canary.0.

---

Update

The change related to the issue is 4f6bb5e.

Custom _document.js (class component + getInitialProps) is not compatible with React 18 Stream SSR at the moment. However, since the commit mentioned above, Next.js now always uses Stream SSR when React 18 is installed, thus causing the issue.

It also means that any feature provided by Next.js that is not yet supported by React 18 (E.g. next/head) will stop working.

[okisdev]

Hi @SukkaW

Yes. I have tried to downgrade to next@12.1.1 before, it works, but I don't think this is a long-term solution.

I recognize that the changes between 12.1.1 and 12.1.2-canary.0 caused _document.js to malfunction, as you found.

Looking forward to a further answer & solution to this issue.

[timneutkens]

We're working on a fix for this issue in #35736. Will be out on stable today 🙏

[kachkaev]

Looks like the bug is still there in 12.1.3: #35758. Maybe it’s not the same one, but something quite similar.

[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.