Typeahead accessibility failed with screen reader NVDA

[jacques-lebourgeois]

Bug description:
When using a screen reader, the user is not informed on the currently active line in the dropdown list

Plunker/StackBlitz that reproduces the issue:

• Install NVDA screen reader
• Run NVDA
• Go on the example page with min-lenth
• Move down and up in the drop down list
• The screen reader just read "Vide" (in french, that means empty in english)

Versions of ngx-bootstrap, Angular, and Bootstrap:

ngx-bootstrap: last one

Angular: last one

Bootstrap: last one

Build system: Angular CLI, System.js, webpack, starter seed:

Expected behavior

To make in work in our Angular project, we create a complentary directive that had aria-activedescendant="ngb-typeahead-0-0"
to the input element and aria-selected="true|false" to each button of the ldropdown list