never pass undefined to HTMLElement.insertBefore(), #715

phetsims · Jun 15, 2018 · 5fb9122 · 5fb9122
1 parent 71b38c1
commit 5fb9122
Showing 1 changed file with 5 additions and 2 deletions.
diff --git a/js/accessibility/AccessiblePeer.js b/js/accessibility/AccessiblePeer.js
@@ -86,8 +86,8 @@ define( function( require ) {
         // The first child of the container parent element should be the peer dom element
         // if undefined, the insertBefore method will insert the primarySiblingDOMElement as the first child
         var primarySiblingDOMElement = this.primarySibling;
-        var firstChild = this.containerParent.children[ 0 ];
-        this.containerParent.insertBefore( primarySiblingDOMElement, firstChild );
+        var firstChild = this.containerParent.children[ 0 ] || null;
+        this.containerParent.insertBefore( primarySiblingDOMElement, firstChild  );
       }
 
       // @private {boolean} - Whether we are currently in a "disposed" (in the pool) state, or are available to be
@@ -143,6 +143,9 @@ define( function( require ) {
       return this.containerParent || this.primarySibling;
     },
 
+    getTopLevelElements: function(){
+    },
+
     /**
      * Get an element on this node, looked up by the association flag passed in.
      * @public (scenery-internal)