findDOMNode deprecation warning with newest react 18 version

[Xellon]

Describe the bug (current behavior)

With newest React 18 version when certain iTwinUi-react components are used and app is in strict mode, an error is logged into the console: findDOMNode is deprecated in StrictMode.

The error is coming from 'react-transition-group' package that is used in WithCSSTransition component. As I understand according to issue reactjs/react-transition-group#904 this can be fixed on iTwinUI side.

Expected Behavior

No response

Link to minimal repro

No response

Steps To Reproduce

1. Create an app that is using React 18 and is wrapped in strict mode.
2. Use one of the affected components, e.g. WithCSSTransition
3. You should be seeing the error in browser console when affected component is rendered

Anything else?

No response

[mayank99]

@Xellon Thanks for reporting this issue. This is something we're aware of, and we're actually planning to remove the dependency on react-transition-group altogether.

[MartynasStrazdas]

Any news on this issue?

[mayank99]

There isn't much news, except that it is still planned. Now that React 19 has been released, we have prioritized this and other tasks related to supporting React 19.

[Antanas-Bentley]

Hi all, with React19 being out already, we are blocked on upgrading due to reliance on findDOMNode from <Dialog /> component. Any updates on this? @mayank99

Crash callstack in React19 based app:

[mayank99]

@Antanas-Bentley We are actively working on it; I think we are going to drop the dependency on react-transition-group and replace them with no transitions for now. Out of curiosity, are all your other dependencies ready for React 19?

[Antanas-Bentley]

@mayank99 Hey, thanks for the quick reply. For me the situation is a bit lighter as I'm developing a dashboard with CRUD. There are not many deps at all besides the design system and tanstack-query (they do support 19). I thought I'd seize the opportunity to try out react19 without much effort due to the codebase being minimal. This is not a pressing issue for me now just wanted to reach out with the error I saw, thanks!