Render doesn't render the same result in react 19

[michielmetcake]

• @testing-library/react version: 16.3.0
• Testing Framework and version:
  "jest": "^30.0.5",
• DOM Environment:
  "jest-environment-jsdom": "^30.0.5",

Relevant code or config:

import { render } from "@testing-library/react";

describe( () => {
  it(() => {
    const {container} = render(<link rel="preconnect" key="bla" href='/bla' />);

    expect(container).toMatchSnapshot()
  });
});

What you did:

We want to update to react 19. But the tests made with testing-library are failing.

What happened:

When running the test from above this is the snapshot we receive:

    - Snapshot  - 6
    + Received  + 1

    - <div>
    -   <link
    -     href="/bla"
    -     rel="preconnect"
    -   />
    - </div>
    + <div />

Reproduction:

https://codesandbox.io/p/devbox/zf2xft?file=%2Fpackage.json%3A14%2C3-15%2C26

Change the version of react to:

"react": "19.1.0",
"react-dom": "19.1.0"

Problem description:

• inconsistent testing response between react versions