next@12.1.6 jest failed tests with dynamic imports

[OlesZadorozhnyy]

Verify canary release

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

Provide environment information

---

What browser are you using? (if relevant)

No response

How are you deploying your application? (if relevant)

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Describe the Bug

All components that have dynamic imports started failing in tests. Jest doesn't see it synchronously. Only with Jest API method waitFor it works.

Expected Behavior

Tests with components that have dynamic imports works as before (v.12.1.5)

To Reproduce

• Use next@12.1.6
• Create component which dynamically imports another component
• Create jest test which checks element from dynamic component (without waitFor)

[OlesZadorozhnyy]

From v12.1.6-canary.9 it's started failing

[bossley9]

I'm also getting this failure with jest 27.4.7.

[balazsorban44]

Does anyone have a simple but complete reproduction? 🙏

[bossley9]

It's reproducible with the with-jest NextJS example https://github.com/vercel/next.js/tree/canary/examples/with-jest with a few tweaks.

Component.tsx:

export default function () {
  return <h1>Hello world!</h1>;
}

pages/index.tsx:

...
import dynamic from "next/dynamic"
const Component = dynamic(() => import("../Component"));

export default function Home() {
  return (
    ...
    <Component />
  )
}

__tests__/index.test.tsx:

import { render, screen, waitFor } from "@testing-library/react";
import Home from "@/pages/index";

describe("Home", () => {
  it("renders a heading", async () => {
    render(<Home />);

    // this will fail
    expect(
      screen.getByRole("heading", { name: "Hello world!" })
    ).toBeInTheDocument();

    // this will not fail
    await waitFor(() => {
      expect(
        screen.getByRole("heading", { name: "Hello world!" })
      ).toBeInTheDocument();
    });
  });
})

As a side note it seems like jest in the default example can't import css modules so I commented them out.

[timneutkens]

Looking at the release it might be related to the changes in #36464

[schorfES]

This applies also for snapshot tests. Sadly, the waitFor approach isn't feasible for snapshot tests when having more than one dynamic inside.

[balazsorban44]

This issue has been automatically closed because it received no activity for a month and had no reproduction to investigate. If you think this was closed by accident, please leave a comment. If you are running into a similar issue, please open a new issue with a reproduction. Thank you.

[bossley9]

@OlesZadorozhnyy can you change the description of this issue to include a reproduction? I've written a reproduction in a comment.

[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.