8039387: Nashorn supports indexed access of List elements, but length property is not supported

Reviewed-by: lagergren, jlaskey

nashorn/src/jdk/internal/dynalink/beans/BeanLinker.java

@@ -113,6 +113,8 @@ class BeanLinker extends AbstractJavaLinker implements TypeBasedGuardingDynamicL
             // explicit property is beneficial for them.
             // REVISIT: is it maybe a code smell that "dyn:getLength" is not needed?
             setPropertyGetter("length", GET_ARRAY_LENGTH, ValidationType.IS_ARRAY);
+        } else if(List.class.isAssignableFrom(clazz)) {
+            setPropertyGetter("length", GET_COLLECTION_LENGTH, ValidationType.INSTANCE_OF);
         }
     }
 

nashorn/test/script/basic/JDK-8039387.js

@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ * 
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ * 
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ * 
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ * 
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/**
+ * JDK-8039387: Nashorn supports indexed access of List elements, but length property is not supported
+ *
+ * @test
+ * @run
+ */
+
+var ArrayList = Java.type("java.util.ArrayList")
+var list = new ArrayList(3)
+list.add("nashorn")
+list.add("js")
+list.add("ecmascript")
+var len = list.length
+print("length = " + len)
+for (var i = 0; i < len; i++)
+    print(list[i])

nashorn/test/script/basic/JDK-8039387.js.EXPECTED

@@ -0,0 +1,4 @@
+length = 3
+nashorn
+js
+ecmascript

nashorn/test/script/basic/list.js

@@ -33,7 +33,7 @@ print("l.class.name=" + Java.typeName(l.class)) // Has "class" property like any
 l.add("foo")
 l.add("bar")
 
-print("l.length=" + l.length) // doesn't work, returns undefined
+print("l.length=" + l.length) // works, maps to l.size()
 print("l.size()=" + l.size()) // this will work
 
 print("l[0]=" + l[0])

nashorn/test/script/basic/list.js.EXPECTED

@@ -1,5 +1,5 @@
 l.class.name=java.util.ArrayList
-l.length=undefined
+l.length=2
 l.size()=2
 l[0]=foo
 l[1]=bar