Implement Object.prototype.{hasOwnProperty, propertyIsEnumerable} for proxies.

src/v8natives.js

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 214 matching lines @@
 
 
 // ECMA-262 - 15.2.4.4
 function ObjectValueOf() {
   return ToObject(this);
 }
 
 
 // ECMA-262 - 15.2.4.5
 function ObjectHasOwnProperty(V) {
+  if (%IsJSProxy(this)) {
+    var handler = %GetHandler(this);
+    return CallTrap1(handler, "hasOwn", TO_STRING_INLINE(V), DerivedHasOwnTrap);
+  }
   return %HasLocalProperty(TO_OBJECT_INLINE(this), TO_STRING_INLINE(V));
 }
 
 
 // ECMA-262 - 15.2.4.6
 function ObjectIsPrototypeOf(V) {
   if (IS_NULL_OR_UNDEFINED(this) && !IS_UNDETECTABLE(this)) {
     throw MakeTypeError("called_on_null_or_undefined",
                         ["Object.prototype.isPrototypeOf"]);
   }
   if (!IS_SPEC_OBJECT(V)) return false;
   return %IsInPrototypeChain(this, V);
 }
 
 
 // ECMA-262 - 15.2.4.6
 function ObjectPropertyIsEnumerable(V) {
-  return %IsPropertyEnumerable(ToObject(this), ToString(V));
+  var P = ToString(V);
+  if (%IsJSProxy(this)) {
+    var desc = GetOwnProperty(this, P);
+    return IS_UNDEFINED(desc) ? false : desc.isEnumerable();
+  }
+  return %IsPropertyEnumerable(ToObject(this), P);
 }
 
 
 // Extensions for providing property getters and setters.
 function ObjectDefineGetter(name, fun) {
   var receiver = this;
   if (receiver == null && !IS_UNDETECTABLE(receiver)) {
     receiver = %GlobalReceiver(global);
   }
   if (!IS_FUNCTION(fun)) {
@@ skipping 40 matching lines @@
   }
   return %LookupAccessor(ToObject(receiver), ToString(name), SETTER);
 }
 
 
 function ObjectKeys(obj) {
   if (!IS_SPEC_OBJECT(obj))
     throw MakeTypeError("obj_ctor_property_non_object", ["keys"]);
   if (%IsJSProxy(obj)) {
     var handler = %GetHandler(obj);
-    var keys = handler.keys;
-    if (IS_UNDEFINED(keys)) keys = DerivedKeysTrap;
-    var names = %_CallFunction(handler, keys);
+    var names = CallTrap0(handler, "keys", DerivedKeysTrap);
     return ToStringArray(names);
   }
   return %LocalKeys(obj);
 }
 
 
 // ES5 8.10.1.
 function IsAccessorDescriptor(desc) {
   if (IS_UNDEFINED(desc)) return false;
   return desc.hasGetter() || desc.hasSetter();
@@ skipping 250 matching lines @@
     desc.setValue(desc_array[VALUE_INDEX]);
     desc.setWritable(desc_array[WRITABLE_INDEX]);
   }
   desc.setEnumerable(desc_array[ENUMERABLE_INDEX]);
   desc.setConfigurable(desc_array[CONFIGURABLE_INDEX]);
 
   return desc;
 }
 
 
+// For Harmony proxies.
+function GetTrap(handler, name, defaultTrap) {
+  var trap = handler[name];
+  if (IS_UNDEFINED(trap)) {
+    if (IS_UNDEFINED(defaultTrap)) {
+      throw MakeTypeError("handler_trap_missing", [handler, name]);
+    }
+    trap = defaultTrap;
+  } else if (!IS_FUNCTION(trap)) {
+    throw MakeTypeError("handler_trap_must_be_callable", [handler, name]);
+  }
+  return trap;
+}
+
+
+function CallTrap0(handler, name, defaultTrap) {
+  return %_CallFunction(handler, GetTrap(handler, name, defaultTrap));
+}
+
+
+function CallTrap1(handler, name, x, defaultTrap) {

[Mads Ager (chromium), 2011/07/19 15:41:05]

Maybe put the arguments last in the parameter list so it is always: (handler,
name, defaultTrap, arg0, ...).

Ahhh, the default trap is optional. Can we require it and explicitly use "void
0" to pass undefined?

[rossberg, 2011/07/21 11:08:42]

Done.

+  return %_CallFunction(handler, x, GetTrap(handler, name, defaultTrap));
+}
+
+
+function CallTrap2(handler, name, x, y, defaultTrap) {
+  return %_CallFunction(handler, x, y, GetTrap(handler, name, defaultTrap));
+}
+
+
 // ES5 section 8.12.2.
 function GetProperty(obj, p) {
   if (%IsJSProxy(obj)) {
     var handler = %GetHandler(obj);
-    var getProperty = handler.getPropertyDescriptor;
-    if (IS_UNDEFINED(getProperty)) {
-      throw MakeTypeError("handler_trap_missing",
-                          [handler, "getPropertyDescriptor"]);
-    }
-    var descriptor = %_CallFunction(handler, p, getProperty);
+    var descriptor = CallTrap1(obj, "getPropertyDescriptor", p);
     if (IS_UNDEFINED(descriptor)) return descriptor;
     var desc = ToCompletePropertyDescriptor(descriptor);
     if (!desc.isConfigurable()) {
       throw MakeTypeError("proxy_prop_not_configurable",
                           [handler, "getPropertyDescriptor", p, descriptor]);
     }
     return desc;
   }
   var prop = GetOwnProperty(obj);
   if (!IS_UNDEFINED(prop)) return prop;
   var proto = %GetPrototype(obj);
   if (IS_NULL(proto)) return void 0;
   return GetProperty(proto, p);
 }
 
 
 // ES5 section 8.12.6
 function HasProperty(obj, p) {
   if (%IsJSProxy(obj)) {
     var handler = %GetHandler(obj);
-    var has = handler.has;
-    if (IS_UNDEFINED(has)) has = DerivedHasTrap;
-    return ToBoolean(%_CallFunction(handler, obj, p, has));
+    return ToBoolean(CallTrap1(handler, "has", p, DerivedHasTrap));
   }
   var desc = GetProperty(obj, p);
   return IS_UNDEFINED(desc) ? false : true;
 }
 
 
 // ES5 section 8.12.1.
-function GetOwnProperty(obj, p) {
+function GetOwnProperty(obj, v) {
+  var p = ToString(v);
   if (%IsJSProxy(obj)) {
     var handler = %GetHandler(obj);
-    var getOwnProperty = handler.getOwnPropertyDescriptor;
-    if (IS_UNDEFINED(getOwnProperty)) {
-      throw MakeTypeError("handler_trap_missing",
-                          [handler, "getOwnPropertyDescriptor"]);
-    }
-    var descriptor = %_CallFunction(handler, p, getOwnProperty);
+    var descriptor = CallTrap1(handler, "getOwnPropertyDescriptor", p);
     if (IS_UNDEFINED(descriptor)) return descriptor;
     var desc = ToCompletePropertyDescriptor(descriptor);
     if (!desc.isConfigurable()) {
       throw MakeTypeError("proxy_prop_not_configurable",
                           [handler, "getOwnPropertyDescriptor", p, descriptor]);
     }
     return desc;
   }
 
   // GetOwnProperty returns an array indexed by the constants
   // defined in macros.py.
   // If p is not a property on obj undefined is returned.
-  var props = %GetOwnProperty(ToObject(obj), ToString(p));
+  var props = %GetOwnProperty(ToObject(obj), ToString(v));
 
   // A false value here means that access checks failed.
   if (props === false) return void 0;
 
   return ConvertDescriptorArrayToDescriptor(props);
 }
 
 
 // Harmony proxies.
 function DefineProxyProperty(obj, p, attributes, should_throw) {
   var handler = %GetHandler(obj);
-  var defineProperty = handler.defineProperty;
-  if (IS_UNDEFINED(defineProperty)) {
-    throw MakeTypeError("handler_trap_missing", [handler, "defineProperty"]);
-  }
-  var result = %_CallFunction(handler, p, attributes, defineProperty);
+  var result = CallTrap2(handler, "defineProperty", p, attributes);
   if (!ToBoolean(result)) {
     if (should_throw) {
       throw MakeTypeError("handler_returned_false",
                           [handler, "defineProperty"]);
     } else {
       return false;
     }
   }
   return true;
 }
@@ skipping 208 matching lines @@
 
 
 // ES5 section 15.2.3.4.
 function ObjectGetOwnPropertyNames(obj) {
   if (!IS_SPEC_OBJECT(obj))
     throw MakeTypeError("obj_ctor_property_non_object", ["getOwnPropertyNames"]);
 
   // Special handling for proxies.
   if (%IsJSProxy(obj)) {
     var handler = %GetHandler(obj);
-    var getOwnPropertyNames = handler.getOwnPropertyNames;
-    if (IS_UNDEFINED(getOwnPropertyNames)) {
-      throw MakeTypeError("handler_trap_missing",
-                          [handler, "getOwnPropertyNames"]);
-    }
-    var names = %_CallFunction(handler, getOwnPropertyNames);
+    var names = CallTrap0(handler, "getOwnPropertyNames");
     return ToStringArray(names, "getOwnPropertyNames");
   }
 
   // Find all the indexed properties.
 
   // Get the local element names.
   var propertyNames = %GetLocalElementNames(obj);
 
   // Get names for indexed interceptor properties.
   if (%GetInterceptorInfo(obj) & 1) {
@@ skipping 109 matching lines @@
     var desc = key_values[i + 1];
     DefineOwnProperty(obj, key, desc, true);
   }
   return obj;
 }
 
 
 // Harmony proxies.
 function ProxyFix(obj) {
   var handler = %GetHandler(obj);
-  var fix = handler.fix;
-  if (IS_UNDEFINED(fix)) {
-    throw MakeTypeError("handler_trap_missing", [handler, "fix"]);
-  }
-  var props = %_CallFunction(handler, fix);
+  var props = CallTrap0(handler, "fix");
   if (IS_UNDEFINED(props)) {
     throw MakeTypeError("handler_returned_undefined", [handler, "fix"]);
   }
   %Fix(obj);
   ObjectDefineProperties(obj, props);
 }
 
 
 // ES5 section 15.2.3.8.
 function ObjectSeal(obj) {
@@ skipping 477 matching lines @@
 // ----------------------------------------------------------------------------
 
 function SetupFunction() {
   InstallFunctions($Function.prototype, DONT_ENUM, $Array(
     "bind", FunctionBind,
     "toString", FunctionToString
   ));
 }
 
 SetupFunction();