element which outside of modal can be focused in ios safari

[Elecweb]

Summary:

focus trap is works fine in desktop browser but it doens't work on ios safari.
In ios safari, when you focus, for example, input on modal, you can click up/down arrow to focus another input which is outside of modal.

Steps to reproduce:

1. go to this link https://codesandbox.io/s/n5ny70m2qp on ios safari
2. click "open Modal" button
3. focus input on modal
4. click up/down arrow and you'll see you still can focus on input which's not on modal

Expected behavior:

you shouldn't focus any input/element outside modal's area

Link to example of issue:

https://codesandbox.io/s/n5ny70m2qp

Additional notes:

I tried with iPhone X, iPhone 8 Plus in browserstack and real devices

For now, I use focus-trap-react to fixing this issue. I think react-modal already handle this job so it'd be great if it also works in ios safari

[Elecweb]

after investigation, it look likes clicking up/down arrow for tabbing on ios safari doesn't fire event at all
so handleKeyDown doesn't get called (so it doesn't call scopeTab helper)