groups-object-subclass-sans.js (1203B)
1 // Copyright 2017 the V8 project authors. All rights reserved. 2 // This code is governed by the BSD license found in the LICENSE file. 3 4 /*--- 5 description: > 6 Test the groups object on RegExp subclass results that do not have their own. 7 esid: sec-regexpbuiltinexec 8 features: [regexp-named-groups] 9 info: | 10 Runtime Semantics: RegExpBuiltinExec ( R, S ) 11 24. If _R_ contains any |GroupName|, then 12 a. Let _groups_ be ObjectCreate(*null*). 13 25. Else, 14 a. Let _groups_ be *undefined*. 15 26. Perform ! CreateDataProperty(_A_, `"groups"`, _groups_). 16 ---*/ 17 18 class FakeRegExp extends RegExp { 19 exec(subject) { 20 const fakeResult = ["ab", "a"]; 21 fakeResult.index = 0; 22 // `groups` is not set, triggering prototype lookup. 23 return fakeResult; 24 } 25 }; 26 27 const re = new FakeRegExp(); 28 const result = re.exec("ab"); 29 assert.sameValue(Object.getPrototypeOf(result), Array.prototype); 30 assert.sameValue(false, result.hasOwnProperty("groups")); 31 32 Array.prototype.groups = { a: "b" }; 33 Object.getPrototypeOf(Array.prototype.groups).b = "c"; 34 assert.sameValue("b", "ab".replace(re, "$<a>")); 35 assert.sameValue("c", "ab".replace(re, "$<b>")); 36 Array.prototype.groups = undefined; 37 38 reportCompare(0, 0);