src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/arrays/DeletedArrayFilter.java

@@ -74,13 +74,14 @@
 
         return value;
     }
 
     @Override
-    public void shiftLeft(final int by) {
+    public ArrayData shiftLeft(final int by) {
         super.shiftLeft(by);
         deleted.shiftLeft(by, length());
+        return this;
     }
 
     @Override
     public ArrayData shiftRight(final int by) {
         super.shiftRight(by);