Function prototype properties length and name are configurable (in ES6)

src/org/mozilla/javascript/ArrowFunction.java

@@ -19,7 +19,7 @@ public ArrowFunction(
         this.targetFunction = targetFunction;
         this.boundThis = boundThis;
 
-        ScriptRuntime.setFunctionProtoAndParent(this, scope);
+        ScriptRuntime.setFunctionProtoAndParent(this, cx, scope, false);
 
         Function thrower = ScriptRuntime.typeErrorThrower(cx);
         NativeObject throwing = new NativeObject();

src/org/mozilla/javascript/BaseFunction.java

@@ -22,13 +22,22 @@ public class BaseFunction extends IdScriptableObject implements Function {
     private static final String FUNCTION_CLASS = "Function";
     static final String GENERATOR_FUNCTION_CLASS = "__GeneratorFunction";
 
-    static void init(Scriptable scope, boolean sealed) {
+    static void init(Context cx, Scriptable scope, boolean sealed) {
         BaseFunction obj = new BaseFunction();
         // Function.prototype attributes: see ECMA 15.3.3.1
         obj.prototypePropertyAttributes = DONTENUM | READONLY | PERMANENT;
+        if (cx.getLanguageVersion() >= Context.VERSION_ES6) {
+            obj.setStandardPropertyAttributes(READONLY | DONTENUM);
+        }
         obj.exportAsJSClass(MAX_PROTOTYPE_ID, scope, sealed);
     }
 
+    /** @deprecated Use {@link #init(Context, Scriptable, boolean)} instead */
+    @Deprecated
+    static void init(Scriptable scope, boolean sealed) {
+        init(Context.getContext(), scope, sealed);
+    }
+
     static Object initAsGeneratorFunction(Scriptable scope, boolean sealed) {
         BaseFunction obj = new BaseFunction(true);
         // Function.prototype attributes: see ECMA 15.3.3.1

src/org/mozilla/javascript/BoundFunction.java

@@ -35,7 +35,7 @@ public BoundFunction(
             length = 0;
         }
 
-        ScriptRuntime.setFunctionProtoAndParent(this, scope);
+        ScriptRuntime.setFunctionProtoAndParent(this, cx, scope, false);
 
         Function thrower = ScriptRuntime.typeErrorThrower(cx);
         NativeObject throwing = new NativeObject();

src/org/mozilla/javascript/FunctionObject.java

@@ -142,7 +142,7 @@ public FunctionObject(String name, Member methodOrConstructor, Scriptable scope)
             }
         }
 
-        ScriptRuntime.setFunctionProtoAndParent(this, scope);
+        ScriptRuntime.setFunctionProtoAndParent(this, Context.getCurrentContext(), scope, false);
     }
 
     /**

src/org/mozilla/javascript/JavaMembers.java

@@ -53,7 +53,7 @@ class JavaMembers {
             this.staticMembers = new HashMap<String, Object>();
             this.cl = cl;
             boolean includePrivate = cx.hasFeature(Context.FEATURE_ENHANCED_JAVA_ACCESS);
-            reflect(scope, includeProtected, includePrivate);
+            reflect(cx, scope, includeProtected, includePrivate);
         } finally {
             Context.exit();
         }
@@ -412,7 +412,8 @@ public int hashCode() {
         }
     }
 
-    private void reflect(Scriptable scope, boolean includeProtected, boolean includePrivate) {
+    private void reflect(
+            Context cx, Scriptable scope, boolean includeProtected, boolean includePrivate) {
         // We reflect methods first, because we want overloaded field/method
         // names to be allocated to the NativeJavaMethod before the field
         // gets in the way.
@@ -465,7 +466,7 @@ private void reflect(Scriptable scope, boolean includeProtected, boolean include
                 }
                 NativeJavaMethod fun = new NativeJavaMethod(methodBoxes);
                 if (scope != null) {
-                    ScriptRuntime.setFunctionProtoAndParent(fun, scope);
+                    ScriptRuntime.setFunctionProtoAndParent(fun, cx, scope, false);
                 }
                 ht.put(entry.getKey(), fun);
             }

src/org/mozilla/javascript/NativeFunction.java

@@ -23,7 +23,7 @@ public final void initScriptFunction(Context cx, Scriptable scope) {
 
     public final void initScriptFunction(
             Context cx, Scriptable scope, boolean es6GeneratorFunction) {
-        ScriptRuntime.setFunctionProtoAndParent(this, scope, es6GeneratorFunction);
+        ScriptRuntime.setFunctionProtoAndParent(this, cx, scope, es6GeneratorFunction);
     }
 
     /**

src/org/mozilla/javascript/NativeScript.java

@@ -23,11 +23,17 @@ class NativeScript extends BaseFunction {
 
     private static final Object SCRIPT_TAG = "Script";
 
-    static void init(Scriptable scope, boolean sealed) {
+    static void init(Context cx, Scriptable scope, boolean sealed) {
         NativeScript obj = new NativeScript(null);
         obj.exportAsJSClass(MAX_PROTOTYPE_ID, scope, sealed);
     }
 
+    /** @deprecated Use {@link #init(Context, Scriptable, boolean)} instead */
+    @Deprecated
+    static void init(Scriptable scope, boolean sealed) {
+        init(Context.getContext(), scope, sealed);
+    }
+
     private NativeScript(Script script) {
         this.script = script;
     }

src/org/mozilla/javascript/ScriptRuntime.java

@@ -60,7 +60,7 @@ public int getLength() {
                             return 0;
                         }
                     };
-            ScriptRuntime.setFunctionProtoAndParent(thrower, cx.topCallScope);
+            ScriptRuntime.setFunctionProtoAndParent(thrower, cx, cx.topCallScope, false);
             thrower.preventExtensions();
             cx.typeErrorThrower = thrower;
         }
@@ -146,7 +146,7 @@ public static ScriptableObject initSafeStandardObjects(
         scope.associateValue(LIBRARY_SCOPE_KEY, scope);
         (new ClassCache()).associate(scope);
 
-        BaseFunction.init(scope, sealed);
+        BaseFunction.init(cx, scope, sealed);
         NativeObject.init(scope, sealed);
 
         Scriptable objectProto = ScriptableObject.getObjectPrototype(scope);
@@ -178,7 +178,7 @@ public static ScriptableObject initSafeStandardObjects(
 
         NativeWith.init(scope, sealed);
         NativeCall.init(scope, sealed);
-        NativeScript.init(scope, sealed);
+        NativeScript.init(cx, scope, sealed);
 
         NativeIterator.init(cx, scope, sealed); // Also initializes NativeGenerator & ES6Generator
 
@@ -4263,6 +4263,15 @@ public static void setFunctionProtoAndParent(
         }
     }
 
+    public static void setFunctionProtoAndParent(
+            BaseFunction fn, Context cx, Scriptable scope, boolean es6GeneratorFunction) {
+        setFunctionProtoAndParent(fn, scope, es6GeneratorFunction);
+
+        if (cx != null && cx.getLanguageVersion() >= Context.VERSION_ES6) {
+            fn.setStandardPropertyAttributes(ScriptableObject.READONLY | ScriptableObject.DONTENUM);
+        }
+    }
+
     public static void setObjectProtoAndParent(ScriptableObject object, Scriptable scope) {
         // Compared with function it always sets the scope to top scope
         scope = ScriptableObject.getTopLevelScope(scope);

testsrc/org/mozilla/javascript/tests/es6/NativeFunctionTest.java

@@ -0,0 +1,127 @@
+package org.mozilla.javascript.tests.es6;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.mozilla.javascript.Context;
+import org.mozilla.javascript.ScriptableObject;
+import org.mozilla.javascript.annotations.JSConstructor;
+import org.mozilla.javascript.annotations.JSFunction;
+
+public class NativeFunctionTest {
+    private Context cx;
+    private ScriptableObject scope;
+
+    @Before
+    public void setUp() throws Exception {
+        cx = Context.enter();
+        cx.setLanguageVersion(Context.VERSION_ES6);
+        scope = cx.initStandardObjects();
+        ScriptableObject.defineClass(scope, HelperObject.class);
+    }
+
+    @After
+    public void tearDown() {
+        Context.exit();
+    }
+
+    @Test
+    public void testFunctionPrototypeLength() {
+        Object result =
+                cx.evaluateString(
+                        scope,
+                        "var desc=Object.getOwnPropertyDescriptor(Function.prototype, 'length');\n"
+                                + "var res = 'configurable: ' + desc.configurable;\n"
+                                + "res += '  enumerable: ' + desc.enumerable;\n"
+                                + "res += '  writable: ' + desc.writable;",
+                        "test",
+                        1,
+                        null);
+        assertEquals("configurable: true  enumerable: false  writable: false", result);
+    }
+
+    @Test
+    public void testFunctionPrototypeName() {
+        Object result =
+                cx.evaluateString(
+                        scope,
+                        "var desc=Object.getOwnPropertyDescriptor(Function.prototype, 'name');\n"
+                                + "var res = 'configurable: ' + desc.configurable;\n"
+                                + "res += '  enumerable: ' + desc.enumerable;\n"
+                                + "res += '  writable: ' + desc.writable;",
+                        "test",
+                        1,
+                        null);
+        assertEquals("configurable: true  enumerable: false  writable: false", result);
+    }
+
+    @Test
+    public void testFunctionLength() {
+        Object result =
+                cx.evaluateString(
+                        scope,
+                        "var f=function(){};\n"
+                                + "var desc=Object.getOwnPropertyDescriptor(f, 'length');\n"
+                                + "var res = 'configurable: ' + desc.configurable;\n"
+                                + "res += '  enumerable: ' + desc.enumerable;\n"
+                                + "res += '  writable: ' + desc.writable;",
+                        "test",
+                        1,
+                        null);
+        assertEquals("configurable: true  enumerable: false  writable: false", result);
+    }
+
+    @Test
+    public void testFunctionName() {
+        Object result =
+                cx.evaluateString(
+                        scope,
+                        "var f=function(){};\n"
+                                + "var desc=Object.getOwnPropertyDescriptor(f, 'name');\n"
+                                + "var res = 'configurable: ' + desc.configurable;\n"
+                                + "res += '  enumerable: ' + desc.enumerable;\n"
+                                + "res += '  writable: ' + desc.writable;",
+                        "test",
+                        1,
+                        null);
+        assertEquals("configurable: true  enumerable: false  writable: false", result);
+    }
+
+    @Test
+    public void testFunctionNameJavaObject() {
+        Object result =
+                cx.evaluateString(
+                        scope,
+                        "var f=new HelperObject().foo;\n"
+                                + "var desc=Object.getOwnPropertyDescriptor(f, 'name');\n"
+                                + "var res = 'configurable: ' + desc.configurable;\n"
+                                + "res += '  enumerable: ' + desc.enumerable;\n"
+                                + "res += '  writable: ' + desc.writable;",
+                        "test",
+                        1,
+                        null);
+        assertEquals("configurable: true  enumerable: false  writable: false", result);
+    }
+
+    public static class HelperObject extends ScriptableObject {
+
+        public HelperObject() {}
+
+        @Override
+        public String getClassName() {
+            return "HelperObject";
+        }
+
+        @JSConstructor
+        public void jsConstructorMethod() {
+            put("initialized", this, Boolean.TRUE);
+        }
+
+        @JSFunction("foo")
+        public Object foo() {
+            return "foo()";
+        }
+    }
+}