fixes #88553

src/vs/base/browser/ui/tree/asyncDataTree.ts

@@ -258,7 +258,20 @@ function asObjectTreeOptions<TInput, T, TFilterData>(options?: IAsyncDataTreeOpt
 				e => (options.expandOnlyOnTwistieClick as ((e: T) => boolean))(e.element as T)
 			)
 		),
-		ariaProvider: undefined,
+		ariaProvider: options.ariaProvider && {
+			getPosInSet(el, index) {
+				return options.ariaProvider!.getPosInSet(el.element as T, index);
+			},
+			getSetSize(el, index, listLength) {
+				return options.ariaProvider!.getSetSize(el.element as T, index, listLength);
+			},
+			getRole: options.ariaProvider!.getRole ? (el) => {
+				return options.ariaProvider!.getRole!(el.element as T);
+			} : undefined,
+			isChecked: options.ariaProvider!.isChecked ? (e) => {
+				return options.ariaProvider?.isChecked!(e.element as T);
+			} : undefined
+		},
 		additionalScrollHeight: options.additionalScrollHeight
 	};
 }