Reproduction example

https://codesandbox.io/s/trusting-panka-gvg259

Prerequisites

1. Render an element with an open shadow dom
2. Focus said element
3. Use keyboard to trigger keys

Expected behavior

The focused element should register the keyboard events

Actual behavior

The element does not register the keyboard events

User-event version

^14.4.3

Environment

Testing Library framework: @testing-library/[email protected]
JS framework: [email protected]
Test environment: [email protected]
DOM implementation: [email protected]

Additional context

I identified that the issue is that when getActiveElement gets an element with shadowDom, it gets the active element of the shadowDom. But, the element with shadow dom could be the active one, even if no shadow children are active (tabindex). Then it returns null, instead of returning the element.