trap-is-missing-target-is-proxy.js (1434B)
1 // Copyright (C) 2020 Alexey Shvayka. All rights reserved. 2 // This code is governed by the BSD license found in the LICENSE file. 3 4 /*--- 5 esid: sec-proxy-object-internal-methods-and-internal-slots-defineownproperty-p-desc 6 description: > 7 If "defineProperty" trap is null or undefined, [[DefineOwnProperty]] call 8 is properly forwarded to [[ProxyTarget]] (which is also a Proxy object). 9 info: | 10 [[DefineOwnProperty]] (P, Desc) 11 12 [...] 13 5. Let target be O.[[ProxyTarget]]. 14 6. Let trap be ? GetMethod(handler, "defineProperty"). 15 7. If trap is undefined, then 16 a. Return ? target.[[DefineOwnProperty]](P, Desc). 17 features: [Proxy, Reflect] 18 ---*/ 19 20 var string = new String("str"); 21 var stringTarget = new Proxy(string, {}); 22 var stringProxy = new Proxy(stringTarget, {}); 23 24 assert(Reflect.defineProperty(stringProxy, "4", {value: 4})); 25 assert.sameValue(string[4], 4); 26 27 assert.throws(TypeError, function() { 28 Object.defineProperty(stringProxy, "0", { 29 value: "x", 30 }); 31 }); 32 33 Object.preventExtensions(string); 34 assert(!Reflect.defineProperty(stringProxy, "foo", {value: 5})); 35 36 37 var func = function() {}; 38 var funcTarget = new Proxy(func, {}); 39 var funcProxy = new Proxy(funcTarget, {}); 40 41 Object.defineProperty(funcProxy, "name", {value: "foo"}); 42 assert.sameValue(func.name, "foo"); 43 44 assert.throws(TypeError, function() { 45 Object.defineProperty(funcProxy, "prototype", { 46 set: function(_value) {}, 47 }); 48 }); 49 50 reportCompare(0, 0);