fixed the issue (#8721)

Author: jwoo-msft

source/nodejs/adaptivecards/src/card-elements.ts

@@ -6644,11 +6644,13 @@ class OverflowAction extends Action {
             }
 
             contextMenu.onClose = () => {
+                this.renderedElement?.focus();
                 this.renderedElement?.setAttribute("aria-expanded", "false");
             }
 
             this.renderedElement.setAttribute("aria-expanded", "true");
             contextMenu.popup(this.renderedElement);
+            contextMenu.selectedIndex = 0;
         }
     }
 

source/nodejs/adaptivecards/src/controls/menu-item.ts

@@ -63,8 +63,8 @@ export class MenuItem {
             };
             this._element.onkeydown = (e) => {
                 if (e.key === Constants.keys.enter) {
-                    e.cancelBubble = true;
-
+                    e.stopPropagation();
+                    e.preventDefault();
                     this.click();
                 }
             };

source/nodejs/adaptivecards/src/controls/popup-menu.ts

@@ -21,6 +21,11 @@ export class PopupMenu extends PopupControl {
 
             element.appendChild(renderedItem);
 
+            if (i == 0)
+            {
+                renderedItem.setAttribute("aria-expanded", "true");
+            }
+
             if (i === this.selectedIndex) {
                 renderedItem.focus();
             }
@@ -63,6 +68,7 @@ export class PopupMenu extends PopupControl {
                 }
 
                 this.selectedIndex = selectedItemIndex;
+                this.removeAriaExpanded(selectedItemIndex);
 
                 e.cancelBubble = true;
 
@@ -76,6 +82,7 @@ export class PopupMenu extends PopupControl {
                     if (selectedItemIndex >= this._renderedItems.length) {
                         selectedItemIndex = 0;
                     }
+                    this.removeAriaExpanded(selectedItemIndex);
                 }
 
                 this.selectedIndex = selectedItemIndex;
@@ -101,4 +108,14 @@ export class PopupMenu extends PopupControl {
             this._selectedIndex = index;
         }
     }
+
+    // remove aria-expanded attribute from menu item
+    private removeAriaExpanded(index: number) {
+        if (this._renderedItems[index].getAttribute("aria-expanded") === "true") {
+            this._renderedItems[index].removeAttribute("aria-expanded");
+        }
+    }
+
+
+
 }