usePreventScroll's iOS keyboard reveal fails under React >= 19.3 in Next.js 16.3

[nkalpak]

Provide a general summary of the issue here

On iOS Safari, tapping a text field inside a Modal that sizes itself from --visual-viewport-height leaves the field hidden behind the keyboard. Nothing scrolls it into view, and nothing errors.

When the keyboard opens, Safari fires one resize event on visualViewport, and two listeners run one after the other:

• useViewportSize, added by react-aria-components on Modal mount. It calls setState, which writes --visual-viewport-height, which grows the sheet's padding and makes the body overflow.
• usePreventScroll's reveal, added when the user tapped the field. It measures the scroller straight away and decides how far to scroll.

So the reveal only works if React commits the first listener's update before the second listener runs. That comes down to which bucket getEventPriority puts resize in.

• react-dom 19.2 and earlier group resize with click. The update flushes in the microtask between the two listeners, so the reveal measures a scroller that has already shrunk and overflows. It scrolls correctly.
• The React 19.3 canary moves resize in with scroll and mousemove ([react-dom] Batch updates from resize until next frame react/react#35117). The update now flushes after the whole event finishes. The reveal measures a scroller that has not shrunk yet, so scrollHeight - clientHeight is still 0, the scroll target gets clamped to 0, and scrollTo({top: 0}) does nothing.

🤔 Expected Behavior?

The focused input is correctly scrolled into view

😯 Current Behavior

See above

💁 Possible Solution

I have solved this currently by attaching a visualViewport resize listener, and setting the --visual-viewport-height property directly on the overlay DOM node.

const onResize = () => {
            overlayRef.current?.style.setProperty("--visual-viewport-height", `${visualViewport.height}px`);
        };

🔦 Context

I have built a RAC Modal sheet component for mobile users. The sheet can contain inputs, and sometimes enough inputs that the sheet can scroll, especially when the keyboard opens. The expectation is that when you focus an input and then the keyboard opens, thereby making the input end up out of the screen due to scroll, the input is scrolled back into view so the user can see what they are typing

🖥️ Steps to Reproduce

• Repro nextjs (react >= 19.3) with issue
• Repro vite (react < 19.3) without issue

Link to repository
Link to nextjs sheet
Link to vite sheet

Version

1.17.0

What browsers are you seeing the problem on?

Safari

If other, please specify.

No response

What operating system are you using?

iOS

🧢 Your Company/Team

No response

🕷 Tracking Issue

No response

[snowystinger]

I think this will be fixed by #10102
Can you check against it?

[nkalpak]

Checked it, it fixes reliably on first focus, then it becomes intermittent on the second refocus and onward.
So goes like:

1. Open sheet
2. Focus 6th input - scrolls correctly
3. Unfocus 6th input
4. Focus 6th input - sometimes scrolls, most often doesn't

From my short investigation, it seems like on the second and onward focus, it sometimes hits this branch, which executes the scrollIntoView immediately, before React has had a chance to commit

[nwidynski]

Yes, #10102's scope does not include scrollIntoView in its first pass. I was planning to add runAfterKeyboard inside scrollIntoView in a follow up, which should take care of this as well as the other issue you opened.