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// Copyright 2015 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.
// Flags: --harmony-proxies --strong-mode
// Forwarding proxies adapted from proposal definition
function handlerMaker1(obj) {
return {
getPropertyDescriptor: function(name) {
var desc;
var searchObj = obj;
while (desc === undefined && searchObj != null) {
desc = Object.getOwnPropertyDescriptor(searchObj, name);
searchObj = searchObj.__proto__;
}
// a trapping proxy's properties must always be configurable
if (desc !== undefined) { desc.configurable = true; }
return desc;
},
fix: function() {
if (Object.isFrozen(obj)) {
var result = {};
Object.getOwnPropertyNames(obj).forEach(function(name) {
result[name] = Object.getOwnPropertyDescriptor(obj, name);
});
return result;
}
// As long as obj is not frozen, the proxy won't allow itself to be fixed
return undefined; // will cause a TypeError to be thrown
}
};
}
function handlerMaker2(obj) {
return {
get: function(receiver, name) {
return obj[name];
},
fix: function() {
if (Object.isFrozen(obj)) {
var result = {};
Object.getOwnPropertyNames(obj).forEach(function(name) {
result[name] = Object.getOwnPropertyDescriptor(obj, name);
});
return result;
}
// As long as obj is not frozen, the proxy won't allow itself to be fixed
return undefined; // will cause a TypeError to be thrown
}
};
}
var baseObj = {};
var proxy1 = Proxy.create(handlerMaker1(baseObj));
var proxy2 = Proxy.create(handlerMaker2(baseObj));
var childObj1 = { __proto__: proxy1 };
var childObj2 = { __proto__: proxy2 };
var childObjAccessor1 = { set foo(_){}, set "1"(_){}, __proto__: proxy1 };
var childObjAccessor2 = { set foo(_){}, set "1"(_){}, __proto__: proxy2 };
(function() {
"use strong";
// TODO(conradw): These asserts are sanity checking V8's proxy implementation.
// Strong mode semantics for ES6 proxies still need to be explored.
assertDoesNotThrow(function(){proxy1.foo});
assertDoesNotThrow(function(){proxy1[1]});
assertDoesNotThrow(function(){proxy2.foo});
assertDoesNotThrow(function(){proxy2[1]});
assertDoesNotThrow(function(){childObj1.foo});
assertDoesNotThrow(function(){childObj1[1]});
assertDoesNotThrow(function(){childObj2.foo});
assertDoesNotThrow(function(){childObj2[1]});
assertThrows(function(){baseObj.foo}, TypeError);
assertThrows(function(){baseObj[1]}, TypeError);
assertThrows(function(){childObjAccessor1.foo}, TypeError);
assertThrows(function(){childObjAccessor1[1]}, TypeError);
assertThrows(function(){childObjAccessor2.foo}, TypeError);
assertThrows(function(){childObjAccessor2[1]}, TypeError);
// Once the proxy is no longer trapping, property access should have strong
// semantics.
Object.freeze(baseObj);
Object.freeze(proxy1);
assertThrows(function(){proxy1.foo}, TypeError);
assertThrows(function(){proxy1[1]}, TypeError);
assertThrows(function(){childObj1.foo}, TypeError);
assertThrows(function(){childObj1[1]}, TypeError);
assertThrows(function(){childObjAccessor1.foo}, TypeError);
assertThrows(function(){childObjAccessor1[1]}, TypeError);
Object.freeze(proxy2);
assertThrows(function(){proxy2.foo}, TypeError);
assertThrows(function(){proxy2[1]}, TypeError);
assertThrows(function(){childObj2.foo}, TypeError);
assertThrows(function(){childObj2[1]}, TypeError);
assertThrows(function(){childObjAccessor2.foo}, TypeError);
assertThrows(function(){childObjAccessor2[1]}, TypeError);
})();
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