You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
2200 lines
76 KiB
2200 lines
76 KiB
// Copyright (C) 2011-2012 Software Languages Lab, Vrije Universiteit Brussel |
|
// This code is dual-licensed under both the Apache License and the MPL |
|
|
|
// Licensed under the Apache License, Version 2.0 (the "License"); |
|
// you may not use this file except in compliance with the License. |
|
// You may obtain a copy of the License at |
|
// |
|
// http://www.apache.org/licenses/LICENSE-2.0 |
|
// |
|
// Unless required by applicable law or agreed to in writing, software |
|
// distributed under the License is distributed on an "AS IS" BASIS, |
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
|
// See the License for the specific language governing permissions and |
|
// limitations under the License. |
|
|
|
/* Version: MPL 1.1 |
|
* |
|
* The contents of this file are subject to the Mozilla Public License Version |
|
* 1.1 (the "License"); you may not use this file except in compliance with |
|
* the License. You may obtain a copy of the License at |
|
* http://www.mozilla.org/MPL/ |
|
* |
|
* Software distributed under the License is distributed on an "AS IS" basis, |
|
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License |
|
* for the specific language governing rights and limitations under the |
|
* License. |
|
* |
|
* The Original Code is a shim for the ES-Harmony reflection module |
|
* |
|
* The Initial Developer of the Original Code is |
|
* Tom Van Cutsem, Vrije Universiteit Brussel. |
|
* Portions created by the Initial Developer are Copyright (C) 2011-2012 |
|
* the Initial Developer. All Rights Reserved. |
|
* |
|
* Contributor(s): |
|
* |
|
*/ |
|
|
|
// ---------------------------------------------------------------------------- |
|
|
|
// This file is a polyfill for the upcoming ECMAScript Reflect API, |
|
// including support for Proxies. See the draft specification at: |
|
// http://wiki.ecmascript.org/doku.php?id=harmony:reflect_api |
|
// http://wiki.ecmascript.org/doku.php?id=harmony:direct_proxies |
|
|
|
// For an implementation of the Handler API, see handlers.js, which implements: |
|
// http://wiki.ecmascript.org/doku.php?id=harmony:virtual_object_api |
|
|
|
// This implementation supersedes the earlier polyfill at: |
|
// code.google.com/p/es-lab/source/browse/trunk/src/proxies/DirectProxies.js |
|
|
|
// This code was tested on tracemonkey / Firefox 12 |
|
// (and should run fine on older Firefox versions starting with FF4) |
|
// The code also works correctly on |
|
// v8 --harmony_proxies --harmony_weakmaps (v3.6.5.1) |
|
|
|
// Language Dependencies: |
|
// - ECMAScript 5/strict |
|
// - "old" (i.e. non-direct) Harmony Proxies |
|
// - Harmony WeakMaps |
|
// Patches: |
|
// - Object.{freeze,seal,preventExtensions} |
|
// - Object.{isFrozen,isSealed,isExtensible} |
|
// - Object.getPrototypeOf |
|
// - Object.keys |
|
// - Object.prototype.valueOf |
|
// - Object.prototype.isPrototypeOf |
|
// - Object.prototype.toString |
|
// - Object.prototype.hasOwnProperty |
|
// - Object.getOwnPropertyDescriptor |
|
// - Object.defineProperty |
|
// - Object.defineProperties |
|
// - Object.getOwnPropertyNames |
|
// - Object.getOwnPropertySymbols |
|
// - Object.getPrototypeOf |
|
// - Object.setPrototypeOf |
|
// - Object.assign |
|
// - Function.prototype.toString |
|
// - Date.prototype.toString |
|
// - Array.isArray |
|
// - Array.prototype.concat |
|
// - Proxy |
|
// Adds new globals: |
|
// - Reflect |
|
|
|
// Direct proxies can be created via Proxy(target, handler) |
|
|
|
// ---------------------------------------------------------------------------- |
|
|
|
(function(global){ // function-as-module pattern |
|
"use strict"; |
|
|
|
// === Direct Proxies: Invariant Enforcement === |
|
|
|
// Direct proxies build on non-direct proxies by automatically wrapping |
|
// all user-defined proxy handlers in a Validator handler that checks and |
|
// enforces ES5 invariants. |
|
|
|
// A direct proxy is a proxy for an existing object called the target object. |
|
|
|
// A Validator handler is a wrapper for a target proxy handler H. |
|
// The Validator forwards all operations to H, but additionally |
|
// performs a number of integrity checks on the results of some traps, |
|
// to make sure H does not violate the ES5 invariants w.r.t. non-configurable |
|
// properties and non-extensible, sealed or frozen objects. |
|
|
|
// For each property that H exposes as own, non-configurable |
|
// (e.g. by returning a descriptor from a call to getOwnPropertyDescriptor) |
|
// the Validator handler defines those properties on the target object. |
|
// When the proxy becomes non-extensible, also configurable own properties |
|
// are checked against the target. |
|
// We will call properties that are defined on the target object |
|
// "fixed properties". |
|
|
|
// We will name fixed non-configurable properties "sealed properties". |
|
// We will name fixed non-configurable non-writable properties "frozen |
|
// properties". |
|
|
|
// The Validator handler upholds the following invariants w.r.t. non-configurability: |
|
// - getOwnPropertyDescriptor cannot report sealed properties as non-existent |
|
// - getOwnPropertyDescriptor cannot report incompatible changes to the |
|
// attributes of a sealed property (e.g. reporting a non-configurable |
|
// property as configurable, or reporting a non-configurable, non-writable |
|
// property as writable) |
|
// - getPropertyDescriptor cannot report sealed properties as non-existent |
|
// - getPropertyDescriptor cannot report incompatible changes to the |
|
// attributes of a sealed property. It _can_ report incompatible changes |
|
// to the attributes of non-own, inherited properties. |
|
// - defineProperty cannot make incompatible changes to the attributes of |
|
// sealed properties |
|
// - deleteProperty cannot report a successful deletion of a sealed property |
|
// - hasOwn cannot report a sealed property as non-existent |
|
// - has cannot report a sealed property as non-existent |
|
// - get cannot report inconsistent values for frozen data |
|
// properties, and must report undefined for sealed accessors with an |
|
// undefined getter |
|
// - set cannot report a successful assignment for frozen data |
|
// properties or sealed accessors with an undefined setter. |
|
// - get{Own}PropertyNames lists all sealed properties of the target. |
|
// - keys lists all enumerable sealed properties of the target. |
|
// - enumerate lists all enumerable sealed properties of the target. |
|
// - if a property of a non-extensible proxy is reported as non-existent, |
|
// then it must forever be reported as non-existent. This applies to |
|
// own and inherited properties and is enforced in the |
|
// deleteProperty, get{Own}PropertyDescriptor, has{Own}, |
|
// get{Own}PropertyNames, keys and enumerate traps |
|
|
|
// Violation of any of these invariants by H will result in TypeError being |
|
// thrown. |
|
|
|
// Additionally, once Object.preventExtensions, Object.seal or Object.freeze |
|
// is invoked on the proxy, the set of own property names for the proxy is |
|
// fixed. Any property name that is not fixed is called a 'new' property. |
|
|
|
// The Validator upholds the following invariants regarding extensibility: |
|
// - getOwnPropertyDescriptor cannot report new properties as existent |
|
// (it must report them as non-existent by returning undefined) |
|
// - defineProperty cannot successfully add a new property (it must reject) |
|
// - getOwnPropertyNames cannot list new properties |
|
// - hasOwn cannot report true for new properties (it must report false) |
|
// - keys cannot list new properties |
|
|
|
// Invariants currently not enforced: |
|
// - getOwnPropertyNames lists only own property names |
|
// - keys lists only enumerable own property names |
|
// Both traps may list more property names than are actually defined on the |
|
// target. |
|
|
|
// Invariants with regard to inheritance are currently not enforced. |
|
// - a non-configurable potentially inherited property on a proxy with |
|
// non-mutable ancestry cannot be reported as non-existent |
|
// (An object with non-mutable ancestry is a non-extensible object whose |
|
// [[Prototype]] is either null or an object with non-mutable ancestry.) |
|
|
|
// Changes in Handler API compared to previous harmony:proxies, see: |
|
// http://wiki.ecmascript.org/doku.php?id=strawman:direct_proxies |
|
// http://wiki.ecmascript.org/doku.php?id=harmony:direct_proxies |
|
|
|
// ---------------------------------------------------------------------------- |
|
|
|
// ---- WeakMap polyfill ---- |
|
|
|
// TODO: find a proper WeakMap polyfill |
|
|
|
// define an empty WeakMap so that at least the Reflect module code |
|
// will work in the absence of WeakMaps. Proxy emulation depends on |
|
// actual WeakMaps, so will not work with this little shim. |
|
if (typeof WeakMap === "undefined") { |
|
global.WeakMap = function(){}; |
|
global.WeakMap.prototype = { |
|
get: function(k) { return undefined; }, |
|
set: function(k,v) { throw new Error("WeakMap not supported"); } |
|
}; |
|
} |
|
|
|
// ---- Normalization functions for property descriptors ---- |
|
|
|
function isStandardAttribute(name) { |
|
return /^(get|set|value|writable|enumerable|configurable)$/.test(name); |
|
} |
|
|
|
// Adapted from ES5 section 8.10.5 |
|
function toPropertyDescriptor(obj) { |
|
if (Object(obj) !== obj) { |
|
throw new TypeError("property descriptor should be an Object, given: "+ |
|
obj); |
|
} |
|
var desc = {}; |
|
if ('enumerable' in obj) { desc.enumerable = !!obj.enumerable; } |
|
if ('configurable' in obj) { desc.configurable = !!obj.configurable; } |
|
if ('value' in obj) { desc.value = obj.value; } |
|
if ('writable' in obj) { desc.writable = !!obj.writable; } |
|
if ('get' in obj) { |
|
var getter = obj.get; |
|
if (getter !== undefined && typeof getter !== "function") { |
|
throw new TypeError("property descriptor 'get' attribute must be "+ |
|
"callable or undefined, given: "+getter); |
|
} |
|
desc.get = getter; |
|
} |
|
if ('set' in obj) { |
|
var setter = obj.set; |
|
if (setter !== undefined && typeof setter !== "function") { |
|
throw new TypeError("property descriptor 'set' attribute must be "+ |
|
"callable or undefined, given: "+setter); |
|
} |
|
desc.set = setter; |
|
} |
|
if ('get' in desc || 'set' in desc) { |
|
if ('value' in desc || 'writable' in desc) { |
|
throw new TypeError("property descriptor cannot be both a data and an "+ |
|
"accessor descriptor: "+obj); |
|
} |
|
} |
|
return desc; |
|
} |
|
|
|
function isAccessorDescriptor(desc) { |
|
if (desc === undefined) return false; |
|
return ('get' in desc || 'set' in desc); |
|
} |
|
function isDataDescriptor(desc) { |
|
if (desc === undefined) return false; |
|
return ('value' in desc || 'writable' in desc); |
|
} |
|
function isGenericDescriptor(desc) { |
|
if (desc === undefined) return false; |
|
return !isAccessorDescriptor(desc) && !isDataDescriptor(desc); |
|
} |
|
|
|
function toCompletePropertyDescriptor(desc) { |
|
var internalDesc = toPropertyDescriptor(desc); |
|
if (isGenericDescriptor(internalDesc) || isDataDescriptor(internalDesc)) { |
|
if (!('value' in internalDesc)) { internalDesc.value = undefined; } |
|
if (!('writable' in internalDesc)) { internalDesc.writable = false; } |
|
} else { |
|
if (!('get' in internalDesc)) { internalDesc.get = undefined; } |
|
if (!('set' in internalDesc)) { internalDesc.set = undefined; } |
|
} |
|
if (!('enumerable' in internalDesc)) { internalDesc.enumerable = false; } |
|
if (!('configurable' in internalDesc)) { internalDesc.configurable = false; } |
|
return internalDesc; |
|
} |
|
|
|
function isEmptyDescriptor(desc) { |
|
return !('get' in desc) && |
|
!('set' in desc) && |
|
!('value' in desc) && |
|
!('writable' in desc) && |
|
!('enumerable' in desc) && |
|
!('configurable' in desc); |
|
} |
|
|
|
function isEquivalentDescriptor(desc1, desc2) { |
|
return sameValue(desc1.get, desc2.get) && |
|
sameValue(desc1.set, desc2.set) && |
|
sameValue(desc1.value, desc2.value) && |
|
sameValue(desc1.writable, desc2.writable) && |
|
sameValue(desc1.enumerable, desc2.enumerable) && |
|
sameValue(desc1.configurable, desc2.configurable); |
|
} |
|
|
|
// copied from http://wiki.ecmascript.org/doku.php?id=harmony:egal |
|
function sameValue(x, y) { |
|
if (x === y) { |
|
// 0 === -0, but they are not identical |
|
return x !== 0 || 1 / x === 1 / y; |
|
} |
|
|
|
// NaN !== NaN, but they are identical. |
|
// NaNs are the only non-reflexive value, i.e., if x !== x, |
|
// then x is a NaN. |
|
// isNaN is broken: it converts its argument to number, so |
|
// isNaN("foo") => true |
|
return x !== x && y !== y; |
|
} |
|
|
|
/** |
|
* Returns a fresh property descriptor that is guaranteed |
|
* to be complete (i.e. contain all the standard attributes). |
|
* Additionally, any non-standard enumerable properties of |
|
* attributes are copied over to the fresh descriptor. |
|
* |
|
* If attributes is undefined, returns undefined. |
|
* |
|
* See also: http://wiki.ecmascript.org/doku.php?id=harmony:proxies_semantics |
|
*/ |
|
function normalizeAndCompletePropertyDescriptor(attributes) { |
|
if (attributes === undefined) { return undefined; } |
|
var desc = toCompletePropertyDescriptor(attributes); |
|
// Note: no need to call FromPropertyDescriptor(desc), as we represent |
|
// "internal" property descriptors as proper Objects from the start |
|
for (var name in attributes) { |
|
if (!isStandardAttribute(name)) { |
|
Object.defineProperty(desc, name, |
|
{ value: attributes[name], |
|
writable: true, |
|
enumerable: true, |
|
configurable: true }); |
|
} |
|
} |
|
return desc; |
|
} |
|
|
|
/** |
|
* Returns a fresh property descriptor whose standard |
|
* attributes are guaranteed to be data properties of the right type. |
|
* Additionally, any non-standard enumerable properties of |
|
* attributes are copied over to the fresh descriptor. |
|
* |
|
* If attributes is undefined, will throw a TypeError. |
|
* |
|
* See also: http://wiki.ecmascript.org/doku.php?id=harmony:proxies_semantics |
|
*/ |
|
function normalizePropertyDescriptor(attributes) { |
|
var desc = toPropertyDescriptor(attributes); |
|
// Note: no need to call FromGenericPropertyDescriptor(desc), as we represent |
|
// "internal" property descriptors as proper Objects from the start |
|
for (var name in attributes) { |
|
if (!isStandardAttribute(name)) { |
|
Object.defineProperty(desc, name, |
|
{ value: attributes[name], |
|
writable: true, |
|
enumerable: true, |
|
configurable: true }); |
|
} |
|
} |
|
return desc; |
|
} |
|
|
|
// store a reference to the real ES5 primitives before patching them later |
|
var prim_preventExtensions = Object.preventExtensions, |
|
prim_seal = Object.seal, |
|
prim_freeze = Object.freeze, |
|
prim_isExtensible = Object.isExtensible, |
|
prim_isSealed = Object.isSealed, |
|
prim_isFrozen = Object.isFrozen, |
|
prim_getPrototypeOf = Object.getPrototypeOf, |
|
prim_getOwnPropertyDescriptor = Object.getOwnPropertyDescriptor, |
|
prim_defineProperty = Object.defineProperty, |
|
prim_defineProperties = Object.defineProperties, |
|
prim_keys = Object.keys, |
|
prim_getOwnPropertyNames = Object.getOwnPropertyNames, |
|
prim_getOwnPropertySymbols = Object.getOwnPropertySymbols, |
|
prim_assign = Object.assign, |
|
prim_isArray = Array.isArray, |
|
prim_concat = Array.prototype.concat, |
|
prim_isPrototypeOf = Object.prototype.isPrototypeOf, |
|
prim_hasOwnProperty = Object.prototype.hasOwnProperty; |
|
|
|
// these will point to the patched versions of the respective methods on |
|
// Object. They are used within this module as the "intrinsic" bindings |
|
// of these methods (i.e. the "original" bindings as defined in the spec) |
|
var Object_isFrozen, |
|
Object_isSealed, |
|
Object_isExtensible, |
|
Object_getPrototypeOf, |
|
Object_getOwnPropertyNames; |
|
|
|
/** |
|
* A property 'name' is fixed if it is an own property of the target. |
|
*/ |
|
function isFixed(name, target) { |
|
return ({}).hasOwnProperty.call(target, name); |
|
} |
|
function isSealed(name, target) { |
|
var desc = Object.getOwnPropertyDescriptor(target, name); |
|
if (desc === undefined) { return false; } |
|
return desc.configurable === false; |
|
} |
|
function isSealedDesc(desc) { |
|
return desc !== undefined && desc.configurable === false; |
|
} |
|
|
|
/** |
|
* Performs all validation that Object.defineProperty performs, |
|
* without actually defining the property. Returns a boolean |
|
* indicating whether validation succeeded. |
|
* |
|
* Implementation transliterated from ES5.1 section 8.12.9 |
|
*/ |
|
function isCompatibleDescriptor(extensible, current, desc) { |
|
if (current === undefined && extensible === false) { |
|
return false; |
|
} |
|
if (current === undefined && extensible === true) { |
|
return true; |
|
} |
|
if (isEmptyDescriptor(desc)) { |
|
return true; |
|
} |
|
if (isEquivalentDescriptor(current, desc)) { |
|
return true; |
|
} |
|
if (current.configurable === false) { |
|
if (desc.configurable === true) { |
|
return false; |
|
} |
|
if ('enumerable' in desc && desc.enumerable !== current.enumerable) { |
|
return false; |
|
} |
|
} |
|
if (isGenericDescriptor(desc)) { |
|
return true; |
|
} |
|
if (isDataDescriptor(current) !== isDataDescriptor(desc)) { |
|
if (current.configurable === false) { |
|
return false; |
|
} |
|
return true; |
|
} |
|
if (isDataDescriptor(current) && isDataDescriptor(desc)) { |
|
if (current.configurable === false) { |
|
if (current.writable === false && desc.writable === true) { |
|
return false; |
|
} |
|
if (current.writable === false) { |
|
if ('value' in desc && !sameValue(desc.value, current.value)) { |
|
return false; |
|
} |
|
} |
|
} |
|
return true; |
|
} |
|
if (isAccessorDescriptor(current) && isAccessorDescriptor(desc)) { |
|
if (current.configurable === false) { |
|
if ('set' in desc && !sameValue(desc.set, current.set)) { |
|
return false; |
|
} |
|
if ('get' in desc && !sameValue(desc.get, current.get)) { |
|
return false; |
|
} |
|
} |
|
} |
|
return true; |
|
} |
|
|
|
// ES6 7.3.11 SetIntegrityLevel |
|
// level is one of "sealed" or "frozen" |
|
function setIntegrityLevel(target, level) { |
|
var ownProps = Object_getOwnPropertyNames(target); |
|
var pendingException = undefined; |
|
if (level === "sealed") { |
|
var l = +ownProps.length; |
|
var k; |
|
for (var i = 0; i < l; i++) { |
|
k = String(ownProps[i]); |
|
try { |
|
Object.defineProperty(target, k, { configurable: false }); |
|
} catch (e) { |
|
if (pendingException === undefined) { |
|
pendingException = e; |
|
} |
|
} |
|
} |
|
} else { |
|
// level === "frozen" |
|
var l = +ownProps.length; |
|
var k; |
|
for (var i = 0; i < l; i++) { |
|
k = String(ownProps[i]); |
|
try { |
|
var currentDesc = Object.getOwnPropertyDescriptor(target, k); |
|
if (currentDesc !== undefined) { |
|
var desc; |
|
if (isAccessorDescriptor(currentDesc)) { |
|
desc = { configurable: false } |
|
} else { |
|
desc = { configurable: false, writable: false } |
|
} |
|
Object.defineProperty(target, k, desc); |
|
} |
|
} catch (e) { |
|
if (pendingException === undefined) { |
|
pendingException = e; |
|
} |
|
} |
|
} |
|
} |
|
if (pendingException !== undefined) { |
|
throw pendingException; |
|
} |
|
return Reflect.preventExtensions(target); |
|
} |
|
|
|
// ES6 7.3.12 TestIntegrityLevel |
|
// level is one of "sealed" or "frozen" |
|
function testIntegrityLevel(target, level) { |
|
var isExtensible = Object_isExtensible(target); |
|
if (isExtensible) return false; |
|
|
|
var ownProps = Object_getOwnPropertyNames(target); |
|
var pendingException = undefined; |
|
var configurable = false; |
|
var writable = false; |
|
|
|
var l = +ownProps.length; |
|
var k; |
|
var currentDesc; |
|
for (var i = 0; i < l; i++) { |
|
k = String(ownProps[i]); |
|
try { |
|
currentDesc = Object.getOwnPropertyDescriptor(target, k); |
|
configurable = configurable || currentDesc.configurable; |
|
if (isDataDescriptor(currentDesc)) { |
|
writable = writable || currentDesc.writable; |
|
} |
|
} catch (e) { |
|
if (pendingException === undefined) { |
|
pendingException = e; |
|
configurable = true; |
|
} |
|
} |
|
} |
|
if (pendingException !== undefined) { |
|
throw pendingException; |
|
} |
|
if (level === "frozen" && writable === true) { |
|
return false; |
|
} |
|
if (configurable === true) { |
|
return false; |
|
} |
|
return true; |
|
} |
|
|
|
// ---- The Validator handler wrapper around user handlers ---- |
|
|
|
/** |
|
* @param target the object wrapped by this proxy. |
|
* As long as the proxy is extensible, only non-configurable properties |
|
* are checked against the target. Once the proxy becomes non-extensible, |
|
* invariants w.r.t. non-extensibility are also enforced. |
|
* |
|
* @param handler the handler of the direct proxy. The object emulated by |
|
* this handler is validated against the target object of the direct proxy. |
|
* Any violations that the handler makes against the invariants |
|
* of the target will cause a TypeError to be thrown. |
|
* |
|
* Both target and handler must be proper Objects at initialization time. |
|
*/ |
|
function Validator(target, handler) { |
|
// for non-revokable proxies, these are const references |
|
// for revokable proxies, on revocation: |
|
// - this.target is set to null |
|
// - this.handler is set to a handler that throws on all traps |
|
this.target = target; |
|
this.handler = handler; |
|
} |
|
|
|
Validator.prototype = { |
|
|
|
/** |
|
* If getTrap returns undefined, the caller should perform the |
|
* default forwarding behavior. |
|
* If getTrap returns normally otherwise, the return value |
|
* will be a callable trap function. When calling the trap function, |
|
* the caller is responsible for binding its |this| to |this.handler|. |
|
*/ |
|
getTrap: function(trapName) { |
|
var trap = this.handler[trapName]; |
|
if (trap === undefined) { |
|
// the trap was not defined, |
|
// perform the default forwarding behavior |
|
return undefined; |
|
} |
|
|
|
if (typeof trap !== "function") { |
|
throw new TypeError(trapName + " trap is not callable: "+trap); |
|
} |
|
|
|
return trap; |
|
}, |
|
|
|
// === fundamental traps === |
|
|
|
/** |
|
* If name denotes a fixed property, check: |
|
* - whether targetHandler reports it as existent |
|
* - whether the returned descriptor is compatible with the fixed property |
|
* If the proxy is non-extensible, check: |
|
* - whether name is not a new property |
|
* Additionally, the returned descriptor is normalized and completed. |
|
*/ |
|
getOwnPropertyDescriptor: function(name) { |
|
"use strict"; |
|
|
|
var trap = this.getTrap("getOwnPropertyDescriptor"); |
|
if (trap === undefined) { |
|
return Reflect.getOwnPropertyDescriptor(this.target, name); |
|
} |
|
|
|
name = String(name); |
|
var desc = trap.call(this.handler, this.target, name); |
|
desc = normalizeAndCompletePropertyDescriptor(desc); |
|
|
|
var targetDesc = Object.getOwnPropertyDescriptor(this.target, name); |
|
var extensible = Object.isExtensible(this.target); |
|
|
|
if (desc === undefined) { |
|
if (isSealedDesc(targetDesc)) { |
|
throw new TypeError("cannot report non-configurable property '"+name+ |
|
"' as non-existent"); |
|
} |
|
if (!extensible && targetDesc !== undefined) { |
|
// if handler is allowed to return undefined, we cannot guarantee |
|
// that it will not return a descriptor for this property later. |
|
// Once a property has been reported as non-existent on a non-extensible |
|
// object, it should forever be reported as non-existent |
|
throw new TypeError("cannot report existing own property '"+name+ |
|
"' as non-existent on a non-extensible object"); |
|
} |
|
return undefined; |
|
} |
|
|
|
// at this point, we know (desc !== undefined), i.e. |
|
// targetHandler reports 'name' as an existing property |
|
|
|
// Note: we could collapse the following two if-tests into a single |
|
// test. Separating out the cases to improve error reporting. |
|
|
|
if (!extensible) { |
|
if (targetDesc === undefined) { |
|
throw new TypeError("cannot report a new own property '"+ |
|
name + "' on a non-extensible object"); |
|
} |
|
} |
|
|
|
if (name !== undefined) { |
|
if (!isCompatibleDescriptor(extensible, targetDesc, desc)) { |
|
throw new TypeError("cannot report incompatible property descriptor "+ |
|
"for property '"+name+"'"); |
|
} |
|
} |
|
|
|
if (desc.configurable === false) { |
|
if (targetDesc === undefined || targetDesc.configurable === true) { |
|
// if the property is configurable or non-existent on the target, |
|
// but is reported as a non-configurable property, it may later be |
|
// reported as configurable or non-existent, which violates the |
|
// invariant that if the property might change or disappear, the |
|
// configurable attribute must be true. |
|
throw new TypeError( |
|
"cannot report a non-configurable descriptor " + |
|
"for configurable or non-existent property '" + name + "'"); |
|
} |
|
if ('writable' in desc && desc.writable === false) { |
|
if (targetDesc.writable === true) { |
|
// if the property is non-configurable, writable on the target, |
|
// but is reported as non-configurable, non-writable, it may later |
|
// be reported as non-configurable, writable again, which violates |
|
// the invariant that a non-configurable, non-writable property |
|
// may not change state. |
|
throw new TypeError( |
|
"cannot report non-configurable, writable property '" + name + |
|
"' as non-configurable, non-writable"); |
|
} |
|
} |
|
} |
|
|
|
return desc; |
|
}, |
|
|
|
/** |
|
* In the direct proxies design with refactored prototype climbing, |
|
* this trap is deprecated. For proxies-as-prototypes, instead |
|
* of calling this trap, the get, set, has or enumerate traps are |
|
* called instead. |
|
* |
|
* In this implementation, we "abuse" getPropertyDescriptor to |
|
* support trapping the get or set traps for proxies-as-prototypes. |
|
* We do this by returning a getter/setter pair that invokes |
|
* the corresponding traps. |
|
* |
|
* While this hack works for inherited property access, it has some |
|
* quirks: |
|
* |
|
* In Firefox, this trap is only called after a prior invocation |
|
* of the 'has' trap has returned true. Hence, expect the following |
|
* behavior: |
|
* <code> |
|
* var child = Object.create(Proxy(target, handler)); |
|
* child[name] // triggers handler.has(target, name) |
|
* // if that returns true, triggers handler.get(target, name, child) |
|
* </code> |
|
* |
|
* On v8, the 'in' operator, when applied to an object that inherits |
|
* from a proxy, will call getPropertyDescriptor and walk the proto-chain. |
|
* That calls the below getPropertyDescriptor trap on the proxy. The |
|
* result of the 'in'-operator is then determined by whether this trap |
|
* returns undefined or a property descriptor object. That is why |
|
* we first explicitly trigger the 'has' trap to determine whether |
|
* the property exists. |
|
* |
|
* This has the side-effect that when enumerating properties on |
|
* an object that inherits from a proxy in v8, only properties |
|
* for which 'has' returns true are returned: |
|
* |
|
* <code> |
|
* var child = Object.create(Proxy(target, handler)); |
|
* for (var prop in child) { |
|
* // only enumerates prop if (prop in child) returns true |
|
* } |
|
* </code> |
|
*/ |
|
getPropertyDescriptor: function(name) { |
|
var handler = this; |
|
|
|
if (!handler.has(name)) return undefined; |
|
|
|
return { |
|
get: function() { |
|
return handler.get(this, name); |
|
}, |
|
set: function(val) { |
|
if (handler.set(this, name, val)) { |
|
return val; |
|
} else { |
|
throw new TypeError("failed assignment to "+name); |
|
} |
|
}, |
|
enumerable: true, |
|
configurable: true |
|
}; |
|
}, |
|
|
|
/** |
|
* If name denotes a fixed property, check for incompatible changes. |
|
* If the proxy is non-extensible, check that new properties are rejected. |
|
*/ |
|
defineProperty: function(name, desc) { |
|
// TODO(tvcutsem): the current tracemonkey implementation of proxies |
|
// auto-completes 'desc', which is not correct. 'desc' should be |
|
// normalized, but not completed. Consider: |
|
// Object.defineProperty(proxy, 'foo', {enumerable:false}) |
|
// This trap will receive desc = |
|
// {value:undefined,writable:false,enumerable:false,configurable:false} |
|
// This will also set all other attributes to their default value, |
|
// which is unexpected and different from [[DefineOwnProperty]]. |
|
// Bug filed: https://bugzilla.mozilla.org/show_bug.cgi?id=601329 |
|
|
|
var trap = this.getTrap("defineProperty"); |
|
if (trap === undefined) { |
|
// default forwarding behavior |
|
return Reflect.defineProperty(this.target, name, desc); |
|
} |
|
|
|
name = String(name); |
|
var descObj = normalizePropertyDescriptor(desc); |
|
var success = trap.call(this.handler, this.target, name, descObj); |
|
success = !!success; // coerce to Boolean |
|
|
|
if (success === true) { |
|
|
|
var targetDesc = Object.getOwnPropertyDescriptor(this.target, name); |
|
var extensible = Object.isExtensible(this.target); |
|
|
|
// Note: we could collapse the following two if-tests into a single |
|
// test. Separating out the cases to improve error reporting. |
|
|
|
if (!extensible) { |
|
if (targetDesc === undefined) { |
|
throw new TypeError("cannot successfully add a new property '"+ |
|
name + "' to a non-extensible object"); |
|
} |
|
} |
|
|
|
if (targetDesc !== undefined) { |
|
if (!isCompatibleDescriptor(extensible, targetDesc, desc)) { |
|
throw new TypeError("cannot define incompatible property "+ |
|
"descriptor for property '"+name+"'"); |
|
} |
|
if (isDataDescriptor(targetDesc) && |
|
targetDesc.configurable === false && |
|
targetDesc.writable === true) { |
|
if (desc.configurable === false && desc.writable === false) { |
|
// if the property is non-configurable, writable on the target |
|
// but was successfully reported to be updated to |
|
// non-configurable, non-writable, it can later be reported |
|
// again as non-configurable, writable, which violates |
|
// the invariant that non-configurable, non-writable properties |
|
// cannot change state |
|
throw new TypeError( |
|
"cannot successfully define non-configurable, writable " + |
|
" property '" + name + "' as non-configurable, non-writable"); |
|
} |
|
} |
|
} |
|
|
|
if (desc.configurable === false && !isSealedDesc(targetDesc)) { |
|
// if the property is configurable or non-existent on the target, |
|
// but is successfully being redefined as a non-configurable property, |
|
// it may later be reported as configurable or non-existent, which violates |
|
// the invariant that if the property might change or disappear, the |
|
// configurable attribute must be true. |
|
throw new TypeError( |
|
"cannot successfully define a non-configurable " + |
|
"descriptor for configurable or non-existent property '" + |
|
name + "'"); |
|
} |
|
|
|
} |
|
|
|
return success; |
|
}, |
|
|
|
/** |
|
* On success, check whether the target object is indeed non-extensible. |
|
*/ |
|
preventExtensions: function() { |
|
var trap = this.getTrap("preventExtensions"); |
|
if (trap === undefined) { |
|
// default forwarding behavior |
|
return Reflect.preventExtensions(this.target); |
|
} |
|
|
|
var success = trap.call(this.handler, this.target); |
|
success = !!success; // coerce to Boolean |
|
if (success) { |
|
if (Object_isExtensible(this.target)) { |
|
throw new TypeError("can't report extensible object as non-extensible: "+ |
|
this.target); |
|
} |
|
} |
|
return success; |
|
}, |
|
|
|
/** |
|
* If name denotes a sealed property, check whether handler rejects. |
|
*/ |
|
delete: function(name) { |
|
"use strict"; |
|
var trap = this.getTrap("deleteProperty"); |
|
if (trap === undefined) { |
|
// default forwarding behavior |
|
return Reflect.deleteProperty(this.target, name); |
|
} |
|
|
|
name = String(name); |
|
var res = trap.call(this.handler, this.target, name); |
|
res = !!res; // coerce to Boolean |
|
|
|
var targetDesc; |
|
if (res === true) { |
|
targetDesc = Object.getOwnPropertyDescriptor(this.target, name); |
|
if (targetDesc !== undefined && targetDesc.configurable === false) { |
|
throw new TypeError("property '" + name + "' is non-configurable "+ |
|
"and can't be deleted"); |
|
} |
|
if (targetDesc !== undefined && !Object_isExtensible(this.target)) { |
|
// if the property still exists on a non-extensible target but |
|
// is reported as successfully deleted, it may later be reported |
|
// as present, which violates the invariant that an own property, |
|
// deleted from a non-extensible object cannot reappear. |
|
throw new TypeError( |
|
"cannot successfully delete existing property '" + name + |
|
"' on a non-extensible object"); |
|
} |
|
} |
|
|
|
return res; |
|
}, |
|
|
|
/** |
|
* The getOwnPropertyNames trap was replaced by the ownKeys trap, |
|
* which now also returns an array (of strings or symbols) and |
|
* which performs the same rigorous invariant checks as getOwnPropertyNames |
|
* |
|
* See issue #48 on how this trap can still get invoked by external libs |
|
* that don't use the patched Object.getOwnPropertyNames function. |
|
*/ |
|
getOwnPropertyNames: function() { |
|
// Note: removed deprecation warning to avoid dependency on 'console' |
|
// (and on node, should anyway use util.deprecate). Deprecation warnings |
|
// can also be annoying when they are outside of the user's control, e.g. |
|
// when an external library calls unpatched Object.getOwnPropertyNames. |
|
// Since there is a clean fallback to `ownKeys`, the fact that the |
|
// deprecated method is still called is mostly harmless anyway. |
|
// See also issues #65 and #66. |
|
// console.warn("getOwnPropertyNames trap is deprecated. Use ownKeys instead"); |
|
return this.ownKeys(); |
|
}, |
|
|
|
/** |
|
* Checks whether the trap result does not contain any new properties |
|
* if the proxy is non-extensible. |
|
* |
|
* Any own non-configurable properties of the target that are not included |
|
* in the trap result give rise to a TypeError. As such, we check whether the |
|
* returned result contains at least all sealed properties of the target |
|
* object. |
|
* |
|
* Additionally, the trap result is normalized. |
|
* Instead of returning the trap result directly: |
|
* - create and return a fresh Array, |
|
* - of which each element is coerced to a String |
|
* |
|
* This trap is called a.o. by Reflect.ownKeys, Object.getOwnPropertyNames |
|
* and Object.keys (the latter filters out only the enumerable own properties). |
|
*/ |
|
ownKeys: function() { |
|
var trap = this.getTrap("ownKeys"); |
|
if (trap === undefined) { |
|
// default forwarding behavior |
|
return Reflect.ownKeys(this.target); |
|
} |
|
|
|
var trapResult = trap.call(this.handler, this.target); |
|
|
|
// propNames is used as a set of strings |
|
var propNames = Object.create(null); |
|
var numProps = +trapResult.length; |
|
var result = new Array(numProps); |
|
|
|
for (var i = 0; i < numProps; i++) { |
|
var s = String(trapResult[i]); |
|
if (!Object.isExtensible(this.target) && !isFixed(s, this.target)) { |
|
// non-extensible proxies don't tolerate new own property names |
|
throw new TypeError("ownKeys trap cannot list a new "+ |
|
"property '"+s+"' on a non-extensible object"); |
|
} |
|
|
|
propNames[s] = true; |
|
result[i] = s; |
|
} |
|
|
|
var ownProps = Object_getOwnPropertyNames(this.target); |
|
var target = this.target; |
|
ownProps.forEach(function (ownProp) { |
|
if (!propNames[ownProp]) { |
|
if (isSealed(ownProp, target)) { |
|
throw new TypeError("ownKeys trap failed to include "+ |
|
"non-configurable property '"+ownProp+"'"); |
|
} |
|
if (!Object.isExtensible(target) && |
|
isFixed(ownProp, target)) { |
|
// if handler is allowed to report ownProp as non-existent, |
|
// we cannot guarantee that it will never later report it as |
|
// existent. Once a property has been reported as non-existent |
|
// on a non-extensible object, it should forever be reported as |
|
// non-existent |
|
throw new TypeError("ownKeys trap cannot report existing own property '"+ |
|
ownProp+"' as non-existent on a non-extensible object"); |
|
} |
|
} |
|
}); |
|
|
|
return result; |
|
}, |
|
|
|
/** |
|
* Checks whether the trap result is consistent with the state of the |
|
* wrapped target. |
|
*/ |
|
isExtensible: function() { |
|
var trap = this.getTrap("isExtensible"); |
|
if (trap === undefined) { |
|
// default forwarding behavior |
|
return Reflect.isExtensible(this.target); |
|
} |
|
|
|
var result = trap.call(this.handler, this.target); |
|
result = !!result; // coerce to Boolean |
|
var state = Object_isExtensible(this.target); |
|
if (result !== state) { |
|
if (result) { |
|
throw new TypeError("cannot report non-extensible object as extensible: "+ |
|
this.target); |
|
} else { |
|
throw new TypeError("cannot report extensible object as non-extensible: "+ |
|
this.target); |
|
} |
|
} |
|
return state; |
|
}, |
|
|
|
/** |
|
* Check whether the trap result corresponds to the target's [[Prototype]] |
|
*/ |
|
getPrototypeOf: function() { |
|
var trap = this.getTrap("getPrototypeOf"); |
|
if (trap === undefined) { |
|
// default forwarding behavior |
|
return Reflect.getPrototypeOf(this.target); |
|
} |
|
|
|
var allegedProto = trap.call(this.handler, this.target); |
|
|
|
if (!Object_isExtensible(this.target)) { |
|
var actualProto = Object_getPrototypeOf(this.target); |
|
if (!sameValue(allegedProto, actualProto)) { |
|
throw new TypeError("prototype value does not match: " + this.target); |
|
} |
|
} |
|
|
|
return allegedProto; |
|
}, |
|
|
|
/** |
|
* If target is non-extensible and setPrototypeOf trap returns true, |
|
* check whether the trap result corresponds to the target's [[Prototype]] |
|
*/ |
|
setPrototypeOf: function(newProto) { |
|
var trap = this.getTrap("setPrototypeOf"); |
|
if (trap === undefined) { |
|
// default forwarding behavior |
|
return Reflect.setPrototypeOf(this.target, newProto); |
|
} |
|
|
|
var success = trap.call(this.handler, this.target, newProto); |
|
|
|
success = !!success; |
|
if (success && !Object_isExtensible(this.target)) { |
|
var actualProto = Object_getPrototypeOf(this.target); |
|
if (!sameValue(newProto, actualProto)) { |
|
throw new TypeError("prototype value does not match: " + this.target); |
|
} |
|
} |
|
|
|
return success; |
|
}, |
|
|
|
/** |
|
* In the direct proxies design with refactored prototype climbing, |
|
* this trap is deprecated. For proxies-as-prototypes, for-in will |
|
* call the enumerate() trap. If that trap is not defined, the |
|
* operation is forwarded to the target, no more fallback on this |
|
* fundamental trap. |
|
*/ |
|
getPropertyNames: function() { |
|
throw new TypeError("getPropertyNames trap is deprecated"); |
|
}, |
|
|
|
// === derived traps === |
|
|
|
/** |
|
* If name denotes a fixed property, check whether the trap returns true. |
|
*/ |
|
has: function(name) { |
|
var trap = this.getTrap("has"); |
|
if (trap === undefined) { |
|
// default forwarding behavior |
|
return Reflect.has(this.target, name); |
|
} |
|
|
|
name = String(name); |
|
var res = trap.call(this.handler, this.target, name); |
|
res = !!res; // coerce to Boolean |
|
|
|
if (res === false) { |
|
if (isSealed(name, this.target)) { |
|
throw new TypeError("cannot report existing non-configurable own "+ |
|
"property '"+ name + "' as a non-existent "+ |
|
"property"); |
|
} |
|
if (!Object.isExtensible(this.target) && |
|
isFixed(name, this.target)) { |
|
// if handler is allowed to return false, we cannot guarantee |
|
// that it will not return true for this property later. |
|
// Once a property has been reported as non-existent on a non-extensible |
|
// object, it should forever be reported as non-existent |
|
throw new TypeError("cannot report existing own property '"+name+ |
|
"' as non-existent on a non-extensible object"); |
|
} |
|
} |
|
|
|
// if res === true, we don't need to check for extensibility |
|
// even for a non-extensible proxy that has no own name property, |
|
// the property may have been inherited |
|
|
|
return res; |
|
}, |
|
|
|
/** |
|
* If name denotes a fixed non-configurable, non-writable data property, |
|
* check its return value against the previously asserted value of the |
|
* fixed property. |
|
*/ |
|
get: function(receiver, name) { |
|
|
|
// experimental support for invoke() trap on platforms that |
|
// support __noSuchMethod__ |
|
/* |
|
if (name === '__noSuchMethod__') { |
|
var handler = this; |
|
return function(name, args) { |
|
return handler.invoke(receiver, name, args); |
|
} |
|
} |
|
*/ |
|
|
|
var trap = this.getTrap("get"); |
|
if (trap === undefined) { |
|
// default forwarding behavior |
|
return Reflect.get(this.target, name, receiver); |
|
} |
|
|
|
name = String(name); |
|
var res = trap.call(this.handler, this.target, name, receiver); |
|
|
|
var fixedDesc = Object.getOwnPropertyDescriptor(this.target, name); |
|
// check consistency of the returned value |
|
if (fixedDesc !== undefined) { // getting an existing property |
|
if (isDataDescriptor(fixedDesc) && |
|
fixedDesc.configurable === false && |
|
fixedDesc.writable === false) { // own frozen data property |
|
if (!sameValue(res, fixedDesc.value)) { |
|
throw new TypeError("cannot report inconsistent value for "+ |
|
"non-writable, non-configurable property '"+ |
|
name+"'"); |
|
} |
|
} else { // it's an accessor property |
|
if (isAccessorDescriptor(fixedDesc) && |
|
fixedDesc.configurable === false && |
|
fixedDesc.get === undefined) { |
|
if (res !== undefined) { |
|
throw new TypeError("must report undefined for non-configurable "+ |
|
"accessor property '"+name+"' without getter"); |
|
} |
|
} |
|
} |
|
} |
|
|
|
return res; |
|
}, |
|
|
|
/** |
|
* If name denotes a fixed non-configurable, non-writable data property, |
|
* check that the trap rejects the assignment. |
|
*/ |
|
set: function(receiver, name, val) { |
|
var trap = this.getTrap("set"); |
|
if (trap === undefined) { |
|
// default forwarding behavior |
|
return Reflect.set(this.target, name, val, receiver); |
|
} |
|
|
|
name = String(name); |
|
var res = trap.call(this.handler, this.target, name, val, receiver); |
|
res = !!res; // coerce to Boolean |
|
|
|
// if success is reported, check whether property is truly assignable |
|
if (res === true) { |
|
var fixedDesc = Object.getOwnPropertyDescriptor(this.target, name); |
|
if (fixedDesc !== undefined) { // setting an existing property |
|
if (isDataDescriptor(fixedDesc) && |
|
fixedDesc.configurable === false && |
|
fixedDesc.writable === false) { |
|
if (!sameValue(val, fixedDesc.value)) { |
|
throw new TypeError("cannot successfully assign to a "+ |
|
"non-writable, non-configurable property '"+ |
|
name+"'"); |
|
} |
|
} else { |
|
if (isAccessorDescriptor(fixedDesc) && |
|
fixedDesc.configurable === false && // non-configurable |
|
fixedDesc.set === undefined) { // accessor with undefined setter |
|
throw new TypeError("setting a property '"+name+"' that has "+ |
|
" only a getter"); |
|
} |
|
} |
|
} |
|
} |
|
|
|
return res; |
|
}, |
|
|
|
/** |
|
* Any own enumerable non-configurable properties of the target that are not |
|
* included in the trap result give rise to a TypeError. As such, we check |
|
* whether the returned result contains at least all sealed enumerable properties |
|
* of the target object. |
|
* |
|
* The trap should return an iterator. |
|
* |
|
* However, as implementations of pre-direct proxies still expect enumerate |
|
* to return an array of strings, we convert the iterator into an array. |
|
*/ |
|
enumerate: function() { |
|
var trap = this.getTrap("enumerate"); |
|
if (trap === undefined) { |
|
// default forwarding behavior |
|
var trapResult = Reflect.enumerate(this.target); |
|
var result = []; |
|
var nxt = trapResult.next(); |
|
while (!nxt.done) { |
|
result.push(String(nxt.value)); |
|
nxt = trapResult.next(); |
|
} |
|
return result; |
|
} |
|
|
|
var trapResult = trap.call(this.handler, this.target); |
|
|
|
if (trapResult === null || |
|
trapResult === undefined || |
|
trapResult.next === undefined) { |
|
throw new TypeError("enumerate trap should return an iterator, got: "+ |
|
trapResult); |
|
} |
|
|
|
// propNames is used as a set of strings |
|
var propNames = Object.create(null); |
|
|
|
// var numProps = +trapResult.length; |
|
var result = []; // new Array(numProps); |
|
|
|
// trapResult is supposed to be an iterator |
|
// drain iterator to array as current implementations still expect |
|
// enumerate to return an array of strings |
|
var nxt = trapResult.next(); |
|
|
|
while (!nxt.done) { |
|
var s = String(nxt.value); |
|
if (propNames[s]) { |
|
throw new TypeError("enumerate trap cannot list a "+ |
|
"duplicate property '"+s+"'"); |
|
} |
|
propNames[s] = true; |
|
result.push(s); |
|
nxt = trapResult.next(); |
|
} |
|
|
|
/*for (var i = 0; i < numProps; i++) { |
|
var s = String(trapResult[i]); |
|
if (propNames[s]) { |
|
throw new TypeError("enumerate trap cannot list a "+ |
|
"duplicate property '"+s+"'"); |
|
} |
|
|
|
propNames[s] = true; |
|
result[i] = s; |
|
} */ |
|
|
|
var ownEnumerableProps = Object.keys(this.target); |
|
var target = this.target; |
|
ownEnumerableProps.forEach(function (ownEnumerableProp) { |
|
if (!propNames[ownEnumerableProp]) { |
|
if (isSealed(ownEnumerableProp, target)) { |
|
throw new TypeError("enumerate trap failed to include "+ |
|
"non-configurable enumerable property '"+ |
|
ownEnumerableProp+"'"); |
|
} |
|
if (!Object.isExtensible(target) && |
|
isFixed(ownEnumerableProp, target)) { |
|
// if handler is allowed not to report ownEnumerableProp as an own |
|
// property, we cannot guarantee that it will never report it as |
|
// an own property later. Once a property has been reported as |
|
// non-existent on a non-extensible object, it should forever be |
|
// reported as non-existent |
|
throw new TypeError("cannot report existing own property '"+ |
|
ownEnumerableProp+"' as non-existent on a "+ |
|
"non-extensible object"); |
|
} |
|
} |
|
}); |
|
|
|
return result; |
|
}, |
|
|
|
/** |
|
* The iterate trap is deprecated by the enumerate trap. |
|
*/ |
|
iterate: Validator.prototype.enumerate, |
|
|
|
/** |
|
* Any own non-configurable properties of the target that are not included |
|
* in the trap result give rise to a TypeError. As such, we check whether the |
|
* returned result contains at least all sealed properties of the target |
|
* object. |
|
* |
|
* The trap result is normalized. |
|
* The trap result is not returned directly. Instead: |
|
* - create and return a fresh Array, |
|
* - of which each element is coerced to String, |
|
* - which does not contain duplicates |
|
* |
|
* FIXME: keys trap is deprecated |
|
*/ |
|
/* |
|
keys: function() { |
|
var trap = this.getTrap("keys"); |
|
if (trap === undefined) { |
|
// default forwarding behavior |
|
return Reflect.keys(this.target); |
|
} |
|
|
|
var trapResult = trap.call(this.handler, this.target); |
|
|
|
// propNames is used as a set of strings |
|
var propNames = Object.create(null); |
|
var numProps = +trapResult.length; |
|
var result = new Array(numProps); |
|
|
|
for (var i = 0; i < numProps; i++) { |
|
var s = String(trapResult[i]); |
|
if (propNames[s]) { |
|
throw new TypeError("keys trap cannot list a "+ |
|
"duplicate property '"+s+"'"); |
|
} |
|
if (!Object.isExtensible(this.target) && !isFixed(s, this.target)) { |
|
// non-extensible proxies don't tolerate new own property names |
|
throw new TypeError("keys trap cannot list a new "+ |
|
"property '"+s+"' on a non-extensible object"); |
|
} |
|
|
|
propNames[s] = true; |
|
result[i] = s; |
|
} |
|
|
|
var ownEnumerableProps = Object.keys(this.target); |
|
var target = this.target; |
|
ownEnumerableProps.forEach(function (ownEnumerableProp) { |
|
if (!propNames[ownEnumerableProp]) { |
|
if (isSealed(ownEnumerableProp, target)) { |
|
throw new TypeError("keys trap failed to include "+ |
|
"non-configurable enumerable property '"+ |
|
ownEnumerableProp+"'"); |
|
} |
|
if (!Object.isExtensible(target) && |
|
isFixed(ownEnumerableProp, target)) { |
|
// if handler is allowed not to report ownEnumerableProp as an own |
|
// property, we cannot guarantee that it will never report it as |
|
// an own property later. Once a property has been reported as |
|
// non-existent on a non-extensible object, it should forever be |
|
// reported as non-existent |
|
throw new TypeError("cannot report existing own property '"+ |
|
ownEnumerableProp+"' as non-existent on a "+ |
|
"non-extensible object"); |
|
} |
|
} |
|
}); |
|
|
|
return result; |
|
}, |
|
*/ |
|
|
|
/** |
|
* New trap that reifies [[Call]]. |
|
* If the target is a function, then a call to |
|
* proxy(...args) |
|
* Triggers this trap |
|
*/ |
|
apply: function(target, thisBinding, args) { |
|
var trap = this.getTrap("apply"); |
|
if (trap === undefined) { |
|
return Reflect.apply(target, thisBinding, args); |
|
} |
|
|
|
if (typeof this.target === "function") { |
|
return trap.call(this.handler, target, thisBinding, args); |
|
} else { |
|
throw new TypeError("apply: "+ target + " is not a function"); |
|
} |
|
}, |
|
|
|
/** |
|
* New trap that reifies [[Construct]]. |
|
* If the target is a function, then a call to |
|
* new proxy(...args) |
|
* Triggers this trap |
|
*/ |
|
construct: function(target, args, newTarget) { |
|
var trap = this.getTrap("construct"); |
|
if (trap === undefined) { |
|
return Reflect.construct(target, args, newTarget); |
|
} |
|
|
|
if (typeof target !== "function") { |
|
throw new TypeError("new: "+ target + " is not a function"); |
|
} |
|
|
|
if (newTarget === undefined) { |
|
newTarget = target; |
|
} else { |
|
if (typeof newTarget !== "function") { |
|
throw new TypeError("new: "+ newTarget + " is not a function"); |
|
} |
|
} |
|
return trap.call(this.handler, target, args, newTarget); |
|
} |
|
}; |
|
|
|
// ---- end of the Validator handler wrapper handler ---- |
|
|
|
// In what follows, a 'direct proxy' is a proxy |
|
// whose handler is a Validator. Such proxies can be made non-extensible, |
|
// sealed or frozen without losing the ability to trap. |
|
|
|
// maps direct proxies to their Validator handlers |
|
var directProxies = new WeakMap(); |
|
|
|
// patch Object.{preventExtensions,seal,freeze} so that |
|
// they recognize fixable proxies and act accordingly |
|
Object.preventExtensions = function(subject) { |
|
var vhandler = directProxies.get(subject); |
|
if (vhandler !== undefined) { |
|
if (vhandler.preventExtensions()) { |
|
return subject; |
|
} else { |
|
throw new TypeError("preventExtensions on "+subject+" rejected"); |
|
} |
|
} else { |
|
return prim_preventExtensions(subject); |
|
} |
|
}; |
|
Object.seal = function(subject) { |
|
setIntegrityLevel(subject, "sealed"); |
|
return subject; |
|
}; |
|
Object.freeze = function(subject) { |
|
setIntegrityLevel(subject, "frozen"); |
|
return subject; |
|
}; |
|
Object.isExtensible = Object_isExtensible = function(subject) { |
|
var vHandler = directProxies.get(subject); |
|
if (vHandler !== undefined) { |
|
return vHandler.isExtensible(); |
|
} else { |
|
return prim_isExtensible(subject); |
|
} |
|
}; |
|
Object.isSealed = Object_isSealed = function(subject) { |
|
return testIntegrityLevel(subject, "sealed"); |
|
}; |
|
Object.isFrozen = Object_isFrozen = function(subject) { |
|
return testIntegrityLevel(subject, "frozen"); |
|
}; |
|
Object.getPrototypeOf = Object_getPrototypeOf = function(subject) { |
|
var vHandler = directProxies.get(subject); |
|
if (vHandler !== undefined) { |
|
return vHandler.getPrototypeOf(); |
|
} else { |
|
return prim_getPrototypeOf(subject); |
|
} |
|
}; |
|
|
|
// patch Object.getOwnPropertyDescriptor to directly call |
|
// the Validator.prototype.getOwnPropertyDescriptor trap |
|
// This is to circumvent an assertion in the built-in Proxy |
|
// trapping mechanism of v8, which disallows that trap to |
|
// return non-configurable property descriptors (as per the |
|
// old Proxy design) |
|
Object.getOwnPropertyDescriptor = function(subject, name) { |
|
var vhandler = directProxies.get(subject); |
|
if (vhandler !== undefined) { |
|
return vhandler.getOwnPropertyDescriptor(name); |
|
} else { |
|
return prim_getOwnPropertyDescriptor(subject, name); |
|
} |
|
}; |
|
|
|
// patch Object.defineProperty to directly call |
|
// the Validator.prototype.defineProperty trap |
|
// This is to circumvent two issues with the built-in |
|
// trap mechanism: |
|
// 1) the current tracemonkey implementation of proxies |
|
// auto-completes 'desc', which is not correct. 'desc' should be |
|
// normalized, but not completed. Consider: |
|
// Object.defineProperty(proxy, 'foo', {enumerable:false}) |
|
// This trap will receive desc = |
|
// {value:undefined,writable:false,enumerable:false,configurable:false} |
|
// This will also set all other attributes to their default value, |
|
// which is unexpected and different from [[DefineOwnProperty]]. |
|
// Bug filed: https://bugzilla.mozilla.org/show_bug.cgi?id=601329 |
|
// 2) the current spidermonkey implementation does not |
|
// throw an exception when this trap returns 'false', but instead silently |
|
// ignores the operation (this is regardless of strict-mode) |
|
// 2a) v8 does throw an exception for this case, but includes the rather |
|
// unhelpful error message: |
|
// 'Proxy handler #<Object> returned false from 'defineProperty' trap' |
|
Object.defineProperty = function(subject, name, desc) { |
|
var vhandler = directProxies.get(subject); |
|
if (vhandler !== undefined) { |
|
var normalizedDesc = normalizePropertyDescriptor(desc); |
|
var success = vhandler.defineProperty(name, normalizedDesc); |
|
if (success === false) { |
|
throw new TypeError("can't redefine property '"+name+"'"); |
|
} |
|
return subject; |
|
} else { |
|
return prim_defineProperty(subject, name, desc); |
|
} |
|
}; |
|
|
|
Object.defineProperties = function(subject, descs) { |
|
var vhandler = directProxies.get(subject); |
|
if (vhandler !== undefined) { |
|
var names = Object.keys(descs); |
|
for (var i = 0; i < names.length; i++) { |
|
var name = names[i]; |
|
var normalizedDesc = normalizePropertyDescriptor(descs[name]); |
|
var success = vhandler.defineProperty(name, normalizedDesc); |
|
if (success === false) { |
|
throw new TypeError("can't redefine property '"+name+"'"); |
|
} |
|
} |
|
return subject; |
|
} else { |
|
return prim_defineProperties(subject, descs); |
|
} |
|
}; |
|
|
|
Object.keys = function(subject) { |
|
var vHandler = directProxies.get(subject); |
|
if (vHandler !== undefined) { |
|
var ownKeys = vHandler.ownKeys(); |
|
var result = []; |
|
for (var i = 0; i < ownKeys.length; i++) { |
|
var k = String(ownKeys[i]); |
|
var desc = Object.getOwnPropertyDescriptor(subject, k); |
|
if (desc !== undefined && desc.enumerable === true) { |
|
result.push(k); |
|
} |
|
} |
|
return result; |
|
} else { |
|
return prim_keys(subject); |
|
} |
|
} |
|
|
|
Object.getOwnPropertyNames = Object_getOwnPropertyNames = function(subject) { |
|
var vHandler = directProxies.get(subject); |
|
if (vHandler !== undefined) { |
|
return vHandler.ownKeys(); |
|
} else { |
|
return prim_getOwnPropertyNames(subject); |
|
} |
|
} |
|
|
|
// fixes issue #71 (Calling Object.getOwnPropertySymbols() on a Proxy |
|
// throws an error) |
|
if (prim_getOwnPropertySymbols !== undefined) { |
|
Object.getOwnPropertySymbols = function(subject) { |
|
var vHandler = directProxies.get(subject); |
|
if (vHandler !== undefined) { |
|
// as this shim does not support symbols, a Proxy never advertises |
|
// any symbol-valued own properties |
|
return []; |
|
} else { |
|
return prim_getOwnPropertySymbols(subject); |
|
} |
|
}; |
|
} |
|
|
|
// fixes issue #72 ('Illegal access' error when using Object.assign) |
|
// Object.assign polyfill based on a polyfill posted on MDN: |
|
// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/\ |
|
// Global_Objects/Object/assign |
|
// Note that this polyfill does not support Symbols, but this Proxy Shim |
|
// does not support Symbols anyway. |
|
if (prim_assign !== undefined) { |
|
Object.assign = function (target) { |
|
|
|
// check if any argument is a proxy object |
|
var noProxies = true; |
|
for (var i = 0; i < arguments.length; i++) { |
|
var vHandler = directProxies.get(arguments[i]); |
|
if (vHandler !== undefined) { |
|
noProxies = false; |
|
break; |
|
} |
|
} |
|
if (noProxies) { |
|
// not a single argument is a proxy, perform built-in algorithm |
|
return prim_assign.apply(Object, arguments); |
|
} |
|
|
|
// there is at least one proxy argument, use the polyfill |
|
|
|
if (target === undefined || target === null) { |
|
throw new TypeError('Cannot convert undefined or null to object'); |
|
} |
|
|
|
var output = Object(target); |
|
for (var index = 1; index < arguments.length; index++) { |
|
var source = arguments[index]; |
|
if (source !== undefined && source !== null) { |
|
for (var nextKey in source) { |
|
if (source.hasOwnProperty(nextKey)) { |
|
output[nextKey] = source[nextKey]; |
|
} |
|
} |
|
} |
|
} |
|
return output; |
|
}; |
|
} |
|
|
|
// returns whether an argument is a reference to an object, |
|
// which is legal as a WeakMap key. |
|
function isObject(arg) { |
|
var type = typeof arg; |
|
return (type === 'object' && arg !== null) || (type === 'function'); |
|
}; |
|
|
|
// a wrapper for WeakMap.get which returns the undefined value |
|
// for keys that are not objects (in which case the underlying |
|
// WeakMap would have thrown a TypeError). |
|
function safeWeakMapGet(map, key) { |
|
return isObject(key) ? map.get(key) : undefined; |
|
}; |
|
|
|
// returns a new function of zero arguments that recursively |
|
// unwraps any proxies specified as the |this|-value. |
|
// The primitive is assumed to be a zero-argument method |
|
// that uses its |this|-binding. |
|
function makeUnwrapping0ArgMethod(primitive) { |
|
return function builtin() { |
|
var vHandler = safeWeakMapGet(directProxies, this); |
|
if (vHandler !== undefined) { |
|
return builtin.call(vHandler.target); |
|
} else { |
|
return primitive.call(this); |
|
} |
|
} |
|
}; |
|
|
|
// returns a new function of 1 arguments that recursively |
|
// unwraps any proxies specified as the |this|-value. |
|
// The primitive is assumed to be a 1-argument method |
|
// that uses its |this|-binding. |
|
function makeUnwrapping1ArgMethod(primitive) { |
|
return function builtin(arg) { |
|
var vHandler = safeWeakMapGet(directProxies, this); |
|
if (vHandler !== undefined) { |
|
return builtin.call(vHandler.target, arg); |
|
} else { |
|
return primitive.call(this, arg); |
|
} |
|
} |
|
}; |
|
|
|
Object.prototype.valueOf = |
|
makeUnwrapping0ArgMethod(Object.prototype.valueOf); |
|
Object.prototype.toString = |
|
makeUnwrapping0ArgMethod(Object.prototype.toString); |
|
Function.prototype.toString = |
|
makeUnwrapping0ArgMethod(Function.prototype.toString); |
|
Date.prototype.toString = |
|
makeUnwrapping0ArgMethod(Date.prototype.toString); |
|
|
|
Object.prototype.isPrototypeOf = function builtin(arg) { |
|
// bugfix thanks to Bill Mark: |
|
// built-in isPrototypeOf does not unwrap proxies used |
|
// as arguments. So, we implement the builtin ourselves, |
|
// based on the ECMAScript 6 spec. Our encoding will |
|
// make sure that if a proxy is used as an argument, |
|
// its getPrototypeOf trap will be called. |
|
while (true) { |
|
var vHandler2 = safeWeakMapGet(directProxies, arg); |
|
if (vHandler2 !== undefined) { |
|
arg = vHandler2.getPrototypeOf(); |
|
if (arg === null) { |
|
return false; |
|
} else if (sameValue(arg, this)) { |
|
return true; |
|
} |
|
} else { |
|
return prim_isPrototypeOf.call(this, arg); |
|
} |
|
} |
|
}; |
|
|
|
Array.isArray = function(subject) { |
|
var vHandler = safeWeakMapGet(directProxies, subject); |
|
if (vHandler !== undefined) { |
|
return Array.isArray(vHandler.target); |
|
} else { |
|
return prim_isArray(subject); |
|
} |
|
}; |
|
|
|
function isProxyArray(arg) { |
|
var vHandler = safeWeakMapGet(directProxies, arg); |
|
if (vHandler !== undefined) { |
|
return Array.isArray(vHandler.target); |
|
} |
|
return false; |
|
} |
|
|
|
// Array.prototype.concat internally tests whether one of its |
|
// arguments is an Array, by checking whether [[Class]] == "Array" |
|
// As such, it will fail to recognize proxies-for-arrays as arrays. |
|
// We patch Array.prototype.concat so that it "unwraps" proxies-for-arrays |
|
// by making a copy. This will trigger the exact same sequence of |
|
// traps on the proxy-for-array as if we would not have unwrapped it. |
|
// See <https://github.com/tvcutsem/harmony-reflect/issues/19> for more. |
|
Array.prototype.concat = function(/*...args*/) { |
|
var length; |
|
for (var i = 0; i < arguments.length; i++) { |
|
if (isProxyArray(arguments[i])) { |
|
length = arguments[i].length; |
|
arguments[i] = Array.prototype.slice.call(arguments[i], 0, length); |
|
} |
|
} |
|
return prim_concat.apply(this, arguments); |
|
}; |
|
|
|
// setPrototypeOf support on platforms that support __proto__ |
|
|
|
var prim_setPrototypeOf = Object.setPrototypeOf; |
|
|
|
// patch and extract original __proto__ setter |
|
var __proto__setter = (function() { |
|
var protoDesc = prim_getOwnPropertyDescriptor(Object.prototype,'__proto__'); |
|
if (protoDesc === undefined || |
|
typeof protoDesc.set !== "function") { |
|
return function() { |
|
throw new TypeError("setPrototypeOf not supported on this platform"); |
|
} |
|
} |
|
|
|
// see if we can actually mutate a prototype with the generic setter |
|
// (e.g. Chrome v28 doesn't allow setting __proto__ via the generic setter) |
|
try { |
|
protoDesc.set.call({},{}); |
|
} catch (e) { |
|
return function() { |
|
throw new TypeError("setPrototypeOf not supported on this platform"); |
|
} |
|
} |
|
|
|
prim_defineProperty(Object.prototype, '__proto__', { |
|
set: function(newProto) { |
|
return Object.setPrototypeOf(this, Object(newProto)); |
|
} |
|
}); |
|
|
|
return protoDesc.set; |
|
}()); |
|
|
|
Object.setPrototypeOf = function(target, newProto) { |
|
var handler = directProxies.get(target); |
|
if (handler !== undefined) { |
|
if (handler.setPrototypeOf(newProto)) { |
|
return target; |
|
} else { |
|
throw new TypeError("proxy rejected prototype mutation"); |
|
} |
|
} else { |
|
if (!Object_isExtensible(target)) { |
|
throw new TypeError("can't set prototype on non-extensible object: " + |
|
target); |
|
} |
|
if (prim_setPrototypeOf) |
|
return prim_setPrototypeOf(target, newProto); |
|
|
|
if (Object(newProto) !== newProto || newProto === null) { |
|
throw new TypeError("Object prototype may only be an Object or null: " + |
|
newProto); |
|
// throw new TypeError("prototype must be an object or null") |
|
} |
|
__proto__setter.call(target, newProto); |
|
return target; |
|
} |
|
} |
|
|
|
Object.prototype.hasOwnProperty = function(name) { |
|
var handler = safeWeakMapGet(directProxies, this); |
|
if (handler !== undefined) { |
|
var desc = handler.getOwnPropertyDescriptor(name); |
|
return desc !== undefined; |
|
} else { |
|
return prim_hasOwnProperty.call(this, name); |
|
} |
|
} |
|
|
|
// ============= Reflection module ============= |
|
// see http://wiki.ecmascript.org/doku.php?id=harmony:reflect_api |
|
|
|
var Reflect = { |
|
getOwnPropertyDescriptor: function(target, name) { |
|
return Object.getOwnPropertyDescriptor(target, name); |
|
}, |
|
defineProperty: function(target, name, desc) { |
|
|
|
// if target is a proxy, invoke its "defineProperty" trap |
|
var handler = directProxies.get(target); |
|
if (handler !== undefined) { |
|
return handler.defineProperty(target, name, desc); |
|
} |
|
|
|
// Implementation transliterated from [[DefineOwnProperty]] |
|
// see ES5.1 section 8.12.9 |
|
// this is the _exact same algorithm_ as the isCompatibleDescriptor |
|
// algorithm defined above, except that at every place it |
|
// returns true, this algorithm actually does define the property. |
|
var current = Object.getOwnPropertyDescriptor(target, name); |
|
var extensible = Object.isExtensible(target); |
|
if (current === undefined && extensible === false) { |
|
return false; |
|
} |
|
if (current === undefined && extensible === true) { |
|
Object.defineProperty(target, name, desc); // should never fail |
|
return true; |
|
} |
|
if (isEmptyDescriptor(desc)) { |
|
return true; |
|
} |
|
if (isEquivalentDescriptor(current, desc)) { |
|
return true; |
|
} |
|
if (current.configurable === false) { |
|
if (desc.configurable === true) { |
|
return false; |
|
} |
|
if ('enumerable' in desc && desc.enumerable !== current.enumerable) { |
|
return false; |
|
} |
|
} |
|
if (isGenericDescriptor(desc)) { |
|
// no further validation necessary |
|
} else if (isDataDescriptor(current) !== isDataDescriptor(desc)) { |
|
if (current.configurable === false) { |
|
return false; |
|
} |
|
} else if (isDataDescriptor(current) && isDataDescriptor(desc)) { |
|
if (current.configurable === false) { |
|
if (current.writable === false && desc.writable === true) { |
|
return false; |
|
} |
|
if (current.writable === false) { |
|
if ('value' in desc && !sameValue(desc.value, current.value)) { |
|
return false; |
|
} |
|
} |
|
} |
|
} else if (isAccessorDescriptor(current) && isAccessorDescriptor(desc)) { |
|
if (current.configurable === false) { |
|
if ('set' in desc && !sameValue(desc.set, current.set)) { |
|
return false; |
|
} |
|
if ('get' in desc && !sameValue(desc.get, current.get)) { |
|
return false; |
|
} |
|
} |
|
} |
|
Object.defineProperty(target, name, desc); // should never fail |
|
return true; |
|
}, |
|
deleteProperty: function(target, name) { |
|
var handler = directProxies.get(target); |
|
if (handler !== undefined) { |
|
return handler.delete(name); |
|
} |
|
|
|
var desc = Object.getOwnPropertyDescriptor(target, name); |
|
if (desc === undefined) { |
|
return true; |
|
} |
|
if (desc.configurable === true) { |
|
delete target[name]; |
|
return true; |
|
} |
|
return false; |
|
}, |
|
getPrototypeOf: function(target) { |
|
return Object.getPrototypeOf(target); |
|
}, |
|
setPrototypeOf: function(target, newProto) { |
|
|
|
var handler = directProxies.get(target); |
|
if (handler !== undefined) { |
|
return handler.setPrototypeOf(newProto); |
|
} |
|
|
|
if (Object(newProto) !== newProto || newProto === null) { |
|
throw new TypeError("Object prototype may only be an Object or null: " + |
|
newProto); |
|
} |
|
|
|
if (!Object_isExtensible(target)) { |
|
return false; |
|
} |
|
|
|
var current = Object.getPrototypeOf(target); |
|
if (sameValue(current, newProto)) { |
|
return true; |
|
} |
|
|
|
if (prim_setPrototypeOf) { |
|
try { |
|
prim_setPrototypeOf(target, newProto); |
|
return true; |
|
} catch (e) { |
|
return false; |
|
} |
|
} |
|
|
|
__proto__setter.call(target, newProto); |
|
return true; |
|
}, |
|
preventExtensions: function(target) { |
|
var handler = directProxies.get(target); |
|
if (handler !== undefined) { |
|
return handler.preventExtensions(); |
|
} |
|
prim_preventExtensions(target); |
|
return true; |
|
}, |
|
isExtensible: function(target) { |
|
return Object.isExtensible(target); |
|
}, |
|
has: function(target, name) { |
|
return name in target; |
|
}, |
|
get: function(target, name, receiver) { |
|
receiver = receiver || target; |
|
|
|
// if target is a proxy, invoke its "get" trap |
|
var handler = directProxies.get(target); |
|
if (handler !== undefined) { |
|
return handler.get(receiver, name); |
|
} |
|
|
|
var desc = Object.getOwnPropertyDescriptor(target, name); |
|
if (desc === undefined) { |
|
var proto = Object.getPrototypeOf(target); |
|
if (proto === null) { |
|
return undefined; |
|
} |
|
return Reflect.get(proto, name, receiver); |
|
} |
|
if (isDataDescriptor(desc)) { |
|
return desc.value; |
|
} |
|
var getter = desc.get; |
|
if (getter === undefined) { |
|
return undefined; |
|
} |
|
return desc.get.call(receiver); |
|
}, |
|
// Reflect.set implementation based on latest version of [[SetP]] at |
|
// http://wiki.ecmascript.org/doku.php?id=harmony:proto_climbing_refactoring |
|
set: function(target, name, value, receiver) { |
|
receiver = receiver || target; |
|
|
|
// if target is a proxy, invoke its "set" trap |
|
var handler = directProxies.get(target); |
|
if (handler !== undefined) { |
|
return handler.set(receiver, name, value); |
|
} |
|
|
|
// first, check whether target has a non-writable property |
|
// shadowing name on receiver |
|
var ownDesc = Object.getOwnPropertyDescriptor(target, name); |
|
|
|
if (ownDesc === undefined) { |
|
// name is not defined in target, search target's prototype |
|
var proto = Object.getPrototypeOf(target); |
|
|
|
if (proto !== null) { |
|
// continue the search in target's prototype |
|
return Reflect.set(proto, name, value, receiver); |
|
} |
|
|
|
// Rev16 change. Cf. https://bugs.ecmascript.org/show_bug.cgi?id=1549 |
|
// target was the last prototype, now we know that 'name' is not shadowed |
|
// by an existing (accessor or data) property, so we can add the property |
|
// to the initial receiver object |
|
// (this branch will intentionally fall through to the code below) |
|
ownDesc = |
|
{ value: undefined, |
|
writable: true, |
|
enumerable: true, |
|
configurable: true }; |
|
} |
|
|
|
// we now know that ownDesc !== undefined |
|
if (isAccessorDescriptor(ownDesc)) { |
|
var setter = ownDesc.set; |
|
if (setter === undefined) return false; |
|
setter.call(receiver, value); // assumes Function.prototype.call |
|
return true; |
|
} |
|
// otherwise, isDataDescriptor(ownDesc) must be true |
|
if (ownDesc.writable === false) return false; |
|
// we found an existing writable data property on the prototype chain. |
|
// Now update or add the data property on the receiver, depending on |
|
// whether the receiver already defines the property or not. |
|
var existingDesc = Object.getOwnPropertyDescriptor(receiver, name); |
|
if (existingDesc !== undefined) { |
|
var updateDesc = |
|
{ value: value, |
|
// FIXME: it should not be necessary to describe the following |
|
// attributes. Added to circumvent a bug in tracemonkey: |
|
// https://bugzilla.mozilla.org/show_bug.cgi?id=601329 |
|
writable: existingDesc.writable, |
|
enumerable: existingDesc.enumerable, |
|
configurable: existingDesc.configurable }; |
|
Object.defineProperty(receiver, name, updateDesc); |
|
return true; |
|
} else { |
|
if (!Object.isExtensible(receiver)) return false; |
|
var newDesc = |
|
{ value: value, |
|
writable: true, |
|
enumerable: true, |
|
configurable: true }; |
|
Object.defineProperty(receiver, name, newDesc); |
|
return true; |
|
} |
|
}, |
|
/*invoke: function(target, name, args, receiver) { |
|
receiver = receiver || target; |
|
|
|
var handler = directProxies.get(target); |
|
if (handler !== undefined) { |
|
return handler.invoke(receiver, name, args); |
|
} |
|
|
|
var fun = Reflect.get(target, name, receiver); |
|
return Function.prototype.apply.call(fun, receiver, args); |
|
},*/ |
|
enumerate: function(target) { |
|
var handler = directProxies.get(target); |
|
var result; |
|
if (handler !== undefined) { |
|
// handler.enumerate should return an iterator directly, but the |
|
// iterator gets converted to an array for backward-compat reasons, |
|
// so we must re-iterate over the array |
|
result = handler.enumerate(handler.target); |
|
} else { |
|
result = []; |
|
for (var name in target) { result.push(name); }; |
|
} |
|
var l = +result.length; |
|
var idx = 0; |
|
return { |
|
next: function() { |
|
if (idx === l) return { done: true }; |
|
return { done: false, value: result[idx++] }; |
|
} |
|
}; |
|
}, |
|
// imperfect ownKeys implementation: in ES6, should also include |
|
// symbol-keyed properties. |
|
ownKeys: function(target) { |
|
return Object_getOwnPropertyNames(target); |
|
}, |
|
apply: function(target, receiver, args) { |
|
// target.apply(receiver, args) |
|
return Function.prototype.apply.call(target, receiver, args); |
|
}, |
|
construct: function(target, args, newTarget) { |
|
// return new target(...args); |
|
|
|
// if target is a proxy, invoke its "construct" trap |
|
var handler = directProxies.get(target); |
|
if (handler !== undefined) { |
|
return handler.construct(handler.target, args, newTarget); |
|
} |
|
|
|
if (typeof target !== "function") { |
|
throw new TypeError("target is not a function: " + target); |
|
} |
|
if (newTarget === undefined || newTarget === target) { |
|
// If newTarget is undefined, then newTarget is set to `target` and |
|
// `Reflect.construct(target, ...args)` becomes equivalent to |
|
// `new target(...args)` |
|
// if `target` is an ES2015 Class constructor, it must be called using |
|
// the `new` operator. Hence we use the new operator on a bound function |
|
// to trigger the [[Construct]] internal method. This technique will work |
|
// for both plain constructor functions and ES2015 classes |
|
return new (Function.prototype.bind.apply(target, [null].concat(args))); |
|
} else { |
|
if (typeof newTarget !== "function") { |
|
throw new TypeError("newTarget is not a function: " + target); |
|
} |
|
// if newTarget is a *different* constructor function, we need to |
|
// emulate [[Construct]] by falling back to [[Call]] with a hand-crafted |
|
// new instance inheriting from newTarget.prototype |
|
// Unfortunately this won't work if target is an ES2015 Constructor |
|
// function, whose [[Call]] method throws an error (it must be invoked |
|
// using the `new` operator) |
|
var proto = newTarget.prototype; |
|
var instance = (Object(proto) === proto) ? Object.create(proto) : {}; |
|
var result = Function.prototype.apply.call(target, instance, args); |
|
return Object(result) === result ? result : instance; |
|
} |
|
} |
|
}; |
|
|
|
// feature-test whether the Reflect global exists |
|
if (global.Reflect !== undefined) { |
|
// Reflect exists, add/override the shimmed methods |
|
Object.getOwnPropertyNames(Reflect).forEach(function (key) { |
|
global.Reflect[key] = Reflect[key]; |
|
}); |
|
} else { |
|
// Reflect doesn't exist, define it as the shimmed Reflect object |
|
global.Reflect = Reflect; |
|
} |
|
|
|
// feature-test whether the Proxy global exists, with |
|
// the harmony-era Proxy.create API |
|
if (typeof Proxy !== "undefined" && |
|
typeof Proxy.create !== "undefined") { |
|
|
|
var primCreate = Proxy.create, |
|
primCreateFunction = Proxy.createFunction; |
|
|
|
var revokedHandler = primCreate({ |
|
get: function() { throw new TypeError("proxy is revoked"); } |
|
}); |
|
|
|
global.Proxy = function(target, handler) { |
|
// check that target is an Object |
|
if (Object(target) !== target) { |
|
throw new TypeError("Proxy target must be an Object, given "+target); |
|
} |
|
// check that handler is an Object |
|
if (Object(handler) !== handler) { |
|
throw new TypeError("Proxy handler must be an Object, given "+handler); |
|
} |
|
|
|
var vHandler = new Validator(target, handler); |
|
var proxy; |
|
if (typeof target === "function") { |
|
proxy = primCreateFunction(vHandler, |
|
// call trap |
|
function() { |
|
var args = Array.prototype.slice.call(arguments); |
|
return vHandler.apply(target, this, args); |
|
}, |
|
// construct trap |
|
function() { |
|
var args = Array.prototype.slice.call(arguments); |
|
return vHandler.construct(target, args); |
|
}); |
|
} else { |
|
proxy = primCreate(vHandler, Object.getPrototypeOf(target)); |
|
} |
|
directProxies.set(proxy, vHandler); |
|
return proxy; |
|
}; |
|
|
|
global.Proxy.revocable = function(target, handler) { |
|
var proxy = new Proxy(target, handler); |
|
var revoke = function() { |
|
var vHandler = directProxies.get(proxy); |
|
if (vHandler !== null) { |
|
vHandler.target = null; |
|
vHandler.handler = revokedHandler; |
|
} |
|
return undefined; |
|
}; |
|
return {proxy: proxy, revoke: revoke}; |
|
} |
|
|
|
// add the old Proxy.create and Proxy.createFunction methods |
|
// so old code that still depends on the harmony-era Proxy object |
|
// is not broken. Also ensures that multiple versions of this |
|
// library should load fine |
|
global.Proxy.create = primCreate; |
|
global.Proxy.createFunction = primCreateFunction; |
|
|
|
} else { |
|
// Proxy global not defined, or old API not available |
|
if (typeof Proxy === "undefined") { |
|
// Proxy global not defined, add a Proxy function stub |
|
global.Proxy = function(_target, _handler) { |
|
throw new Error("proxies not supported on this platform. On v8/node/iojs, make sure to pass the --harmony_proxies flag"); |
|
}; |
|
} |
|
// Proxy global defined but old API not available |
|
// presumably Proxy global already supports new API, leave untouched |
|
} |
|
|
|
// for node.js modules, export every property in the Reflect object |
|
// as part of the module interface |
|
if (typeof exports !== 'undefined') { |
|
Object.keys(Reflect).forEach(function (key) { |
|
exports[key] = Reflect[key]; |
|
}); |
|
} |
|
|
|
// function-as-module pattern |
|
}(typeof exports !== 'undefined' ? global : this)); |