Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1 | // Copyright 2015 the V8 project authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
| 4 | |
| 5 | // Flags: --harmony-proxies --strong-mode |
| 6 | |
| 7 | // Forwarding proxies adapted from proposal definition |
| 8 | function handlerMaker1(obj) { |
| 9 | return { |
| 10 | getPropertyDescriptor: function(name) { |
| 11 | var desc; |
| 12 | var searchObj = obj; |
| 13 | while (desc === undefined && searchObj != null) { |
| 14 | desc = Object.getOwnPropertyDescriptor(searchObj, name); |
| 15 | searchObj = searchObj.__proto__; |
| 16 | } |
| 17 | // a trapping proxy's properties must always be configurable |
| 18 | if (desc !== undefined) { desc.configurable = true; } |
| 19 | return desc; |
| 20 | }, |
| 21 | fix: function() { |
| 22 | if (Object.isFrozen(obj)) { |
| 23 | var result = {}; |
| 24 | Object.getOwnPropertyNames(obj).forEach(function(name) { |
| 25 | result[name] = Object.getOwnPropertyDescriptor(obj, name); |
| 26 | }); |
| 27 | return result; |
| 28 | } |
| 29 | // As long as obj is not frozen, the proxy won't allow itself to be fixed |
| 30 | return undefined; // will cause a TypeError to be thrown |
| 31 | } |
| 32 | }; |
| 33 | } |
| 34 | function handlerMaker2(obj) { |
| 35 | return { |
| 36 | get: function(receiver, name) { |
| 37 | return obj[name]; |
| 38 | }, |
| 39 | fix: function() { |
| 40 | if (Object.isFrozen(obj)) { |
| 41 | var result = {}; |
| 42 | Object.getOwnPropertyNames(obj).forEach(function(name) { |
| 43 | result[name] = Object.getOwnPropertyDescriptor(obj, name); |
| 44 | }); |
| 45 | return result; |
| 46 | } |
| 47 | // As long as obj is not frozen, the proxy won't allow itself to be fixed |
| 48 | return undefined; // will cause a TypeError to be thrown |
| 49 | } |
| 50 | }; |
| 51 | } |
| 52 | var baseObj = {}; |
| 53 | var proxy1 = new Proxy({}, handlerMaker1(baseObj)); |
| 54 | var proxy2 = new Proxy({}, handlerMaker2(baseObj)); |
| 55 | var childObj1 = { __proto__: proxy1 }; |
| 56 | var childObj2 = { __proto__: proxy2 }; |
| 57 | var childObjAccessor1 = { set foo(_){}, set "1"(_){}, __proto__: proxy1 }; |
| 58 | var childObjAccessor2 = { set foo(_){}, set "1"(_){}, __proto__: proxy2 }; |
| 59 | |
| 60 | (function() { |
| 61 | "use strong"; |
| 62 | // TODO(conradw): These asserts are sanity checking V8's proxy implementation. |
| 63 | // Strong mode semantics for ES6 proxies still need to be explored. |
| 64 | assertDoesNotThrow(function(){proxy1.foo}); |
| 65 | assertDoesNotThrow(function(){proxy1[1]}); |
| 66 | assertDoesNotThrow(function(){proxy2.foo}); |
| 67 | assertDoesNotThrow(function(){proxy2[1]}); |
| 68 | assertDoesNotThrow(function(){childObj1.foo}); |
| 69 | assertDoesNotThrow(function(){childObj1[1]}); |
| 70 | assertDoesNotThrow(function(){childObj2.foo}); |
| 71 | assertDoesNotThrow(function(){childObj2[1]}); |
| 72 | assertThrows(function(){baseObj.foo}, TypeError); |
| 73 | assertThrows(function(){baseObj[1]}, TypeError); |
| 74 | assertThrows(function(){childObjAccessor1.foo}, TypeError); |
| 75 | assertThrows(function(){childObjAccessor1[1]}, TypeError); |
| 76 | assertThrows(function(){childObjAccessor2.foo}, TypeError); |
| 77 | assertThrows(function(){childObjAccessor2[1]}, TypeError); |
| 78 | |
| 79 | // Once the proxy is no longer trapping, property access should have strong |
| 80 | // semantics. |
| 81 | Object.freeze(baseObj); |
| 82 | |
| 83 | // TODO(neis): Reenable once proxies properly support freeze. |
| 84 | // |
| 85 | // Object.freeze(proxy1); |
| 86 | // assertThrows(function(){proxy1.foo}, TypeError); |
| 87 | // assertThrows(function(){proxy1[1]}, TypeError); |
| 88 | // assertThrows(function(){childObj1.foo}, TypeError); |
| 89 | // assertThrows(function(){childObj1[1]}, TypeError); |
| 90 | // assertThrows(function(){childObjAccessor1.foo}, TypeError); |
| 91 | // assertThrows(function(){childObjAccessor1[1]}, TypeError); |
| 92 | // |
| 93 | // Object.freeze(proxy2); |
| 94 | // assertThrows(function(){proxy2.foo}, TypeError); |
| 95 | // assertThrows(function(){proxy2[1]}, TypeError); |
| 96 | // assertThrows(function(){childObj2.foo}, TypeError); |
| 97 | // assertThrows(function(){childObj2[1]}, TypeError); |
| 98 | // assertThrows(function(){childObjAccessor2.foo}, TypeError); |
| 99 | // assertThrows(function(){childObjAccessor2[1]}, TypeError); |
| 100 | })(); |