Description
Do you want to request a feature or report a bug?
Bug
What is the current behavior?
<img onLoad={fn} />
does not always trigger fn
when rendered using createRoot if it has siblings which are heavy to render (I think?).
If the current behavior is a bug, please provide the steps to reproduce and if possible a minimal demo of the problem. Your bug will get fixed much faster if we can run your code and it doesn't have dependencies other than React. Paste the link to your JSFiddle (https://jsfiddle.net/Luktwrdm/) or CodeSandbox (https://codesandbox.io/s/new) example below:
https://codesandbox.io/s/quiet-dawn-t1std
You might have to use the retry button a few times, but hopefully you should be able to see it. Don't disable cache while trying
What is the expected behavior?
onLoad always fires if img gets loaded.
Which versions of React, and which browser / OS are affected by this issue? Did this work in previous versions of React?
0.0.0-experimental-f6b8d31a7
Reproduced in chrome and firefox windows. Have not tried the codesandbox in mac, but the actual bug in our app occurred there first so I'd be surprised if it is OS specific.
It does not happen with regular "sync" mode.