Description

The EuiSuperSelect has a child listbox that needs a few adjustments for accessibility. Screenshot and updates listed below.

Recommended adjustments

Additionally, I'd like to recommend two adjustments to the component:

1. Add an accessible label. This label should be an aria-labelledby that references a unique ID (label, span, etc) and the button's own ID. This will create a rich combined label that accurately describes what the super select is doing.
2. Change the tabIndex to -1. This is in line with WAI-ARIA guidance for listbox components.
3. Change the button aria-haspopup to "listbox". This is probably a minor adjustment, but gives a clearer indication to screen readers what the user will be interacting with upon clicking / keying.

Guidance

• https://www.w3.org/WAI/WCAG21/Understanding/name-role-value.html

Screenshots