// Copyright 2018 the V8 project authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. class MyRegExp extends RegExp { exec(str) { const r = super.exec.call(this, str); if (r) r[0] = 0; return r; } } const result = 'a'.match(new MyRegExp('.', 'g')); assertArrayEquals(result, ['0']);