Strict mode Passingnon-Strict mode Passing
Features:
- Symbol.isConcatSpreadable
// Copyright (c) 2014 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. /*--- esid: sec-array.prototype.concat description: Array.prototype.concat array like length valueOf throws features: [Symbol.isConcatSpreadable] ---*/ var objWithPoisonedLengthValueOf = { "length": { valueOf: function() { throw new Test262Error(); }, toString: null }, "1": "A", "3": "B", "5": "C" }; objWithPoisonedLengthValueOf[Symbol.isConcatSpreadable] = true; assert.throws(Test262Error, function() { [].concat(objWithPoisonedLengthValueOf); }, '[].concat(objWithPoisonedLengthValueOf) throws a Test262Error exception');