trap-is-undefined-target-is-proxy.js (1153B)
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-ownpropertykeys 6 description: > 7 If "ownKeys" trap is null or undefined, [[OwnPropertyKeys]] call is 8 properly forwarded to [[ProxyTarget]] (which is also a Proxy object). 9 info: | 10 [[OwnPropertyKeys]] ( ) 11 12 [...] 13 4. Let target be O.[[ProxyTarget]]. 14 5. Let trap be ? GetMethod(handler, "ownKeys"). 15 6. If trap is undefined, then 16 a. Return ? target.[[OwnPropertyKeys]](). 17 18 [[OwnPropertyKeys]] ( ) 19 20 [...] 21 7. Let trapResultArray be ? Call(trap, handler, « target »). 22 8. Let trapResult be ? CreateListFromArrayLike(trapResultArray, « String, Symbol »). 23 [...] 24 23. Return trapResult. 25 includes: [compareArray.js] 26 features: [Symbol, Proxy, Reflect] 27 ---*/ 28 29 var trapResult = [Symbol(), "length", "foo", "0"]; 30 var target = new Proxy([], { 31 ownKeys: function(_target) { 32 return trapResult; 33 }, 34 }); 35 36 var proxy = new Proxy(target, { 37 ownKeys: undefined, 38 }); 39 40 assert.compareArray(Reflect.ownKeys(proxy), trapResult); 41 42 reportCompare(0, 0);