ResizeObserver error thrown when ButtonGroup is used in Widget

[saskliutas]

Describe the bug ResizeObserver loop limit exceeded error is thrown when ButtonGroup component from @itwin/itwinui-react package is used in Widget.

To Reproduce Steps to reproduce the behavior:

1. Clone https://github.com/saskliutas/itwin-viewer-app
2. Setup .env file using instructions in README file
3. Launch app
4. Click Collapse button from Widget in right panel

Expected behavior Error should not be thrown

Screenshots

Desktop (please complete the applicable information):

• OS: Windows
• Browser: Edge, FireFox
• iTwin.js AppUI Version: 3.7.0. (same in 3.5.5)
• iTwin.js Version: 3.7.0 (same in 3.5.5

Additional context Tried to reproduce same error in fresh react app created with vite and create-react-app using only @itwin/itwinui-react. Also tried to reproduce this in iTwin.js sandbox and codesandbox.io. It looks like this error is only thrown in development mode and only when ButtonGroup is used in appui Widget.

[a-gagnon]

Getting the same loop limit exceeded problem when popping out then closing a widget that uses the useLayoutResizeObserver hook. I reverted back to an older version of our code that pulls itwinjs 3.6.0 and it works properly there.

[raplemie]

Hi, OP issue can actually be recreated by using your provided "MyComponent" in a create-react-app but only when using React17 (rather than the default React18, which work fine) I'll follow up with iTwinUI teams and get back to you, we may transfer the issue there.

[raplemie]

Created itwin/itwinui#1317, will close this one. @a-gagnon Please create a different issue if its unrelated to iTwinUI components.