trap-is-undefined-target-is-proxy.js (1170B)
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-hasproperty-p 6 description: > 7 If "has" trap is null or undefined, [[HasProperty]] call is properly 8 forwarded to [[ProxyTarget]] (which is also a Proxy object). 9 info: | 10 [[HasProperty]] ( P ) 11 12 [...] 13 5. Let target be O.[[ProxyTarget]]. 14 6. Let trap be ? GetMethod(handler, "has"). 15 7. If trap is undefined, then 16 a. Return ? target.[[HasProperty]](P). 17 features: [Proxy, Reflect] 18 ---*/ 19 20 var plainObject = { 21 get 0() { 22 return 1; 23 }, 24 foo: 2, 25 set bar(_value) {}, 26 }; 27 28 var plainObjectTarget = new Proxy(plainObject, {}); 29 var plainObjectProxy = new Proxy(plainObjectTarget, { 30 get: undefined, 31 }); 32 33 assert(0 in Object.create(plainObjectProxy)); 34 assert("foo" in plainObjectProxy); 35 assert(Reflect.has(plainObjectProxy, "bar")); 36 37 38 var arrayTarget = new Proxy([1, 2], {}); 39 var arrayProxy = new Proxy(arrayTarget, { 40 get: undefined, 41 }); 42 43 assert("length" in Object.create(arrayProxy)); 44 assert("1" in arrayProxy); 45 assert(!("2" in arrayProxy)); 46 47 reportCompare(0, 0);