Class methods should be non enumerable

src/runtime/runtime-classes.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <stdlib.h>
 #include <limits>
 
 #include "src/v8.h"
 
 #include "src/isolate-inl.h"
@@ skipping 141 matching lines @@
 RUNTIME_FUNCTION(Runtime_DefineClassMethod) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 3);
   CONVERT_ARG_HANDLE_CHECKED(JSObject, object, 0);
   CONVERT_ARG_HANDLE_CHECKED(Name, name, 1);
   CONVERT_ARG_HANDLE_CHECKED(JSFunction, function, 2);
 
   uint32_t index;
   if (name->AsArrayIndex(&index)) {
     RETURN_FAILURE_ON_EXCEPTION(
-        isolate, JSObject::SetOwnElement(object, index, function, STRICT));
+        isolate,
+        JSObject::SetOwnElement(object, index, function, DONT_ENUM, STRICT));
   } else {
     RETURN_FAILURE_ON_EXCEPTION(
-        isolate,
-        JSObject::SetOwnPropertyIgnoreAttributes(object, name, function, NONE));
+        isolate, JSObject::SetOwnPropertyIgnoreAttributes(object, name,
+                                                          function, DONT_ENUM));
   }
   return isolate->heap()->undefined_value();
 }
 
 
 RUNTIME_FUNCTION(Runtime_ClassGetSourceCode) {
   HandleScope shs(isolate);
   DCHECK(args.length() == 1);
   CONVERT_ARG_HANDLE_CHECKED(JSFunction, fun, 0);
 
@@ skipping 258 matching lines @@
   }
 
   Handle<Object> result;
   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
       isolate, result,
       Execution::Call(isolate, proto_function, receiver, argc, argv, false));
   return *result;
 }
 }
 }  // namespace v8::internal