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// Copyright 2016 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.
// Check that @@isConcatSpreadable is checked when set on Object.prototype
// with a dictionary backing store.
// Force Object.prototype into dictionary backing store by adding many
// properties.
for (var i = 0; i < 10*1000; i++) {
Object.prototype['generatedProperty'+i] = true;
}
var array = [1, 2, 3];
var object = {length: 1, '0': 'a'};
function testConcatDefaults() {
assertEquals(array, [].concat(array));
assertEquals(array, array.concat([]));
assertEquals([1, 2, 3, 1, 2, 3], array.concat(array));
assertEquals([object], [].concat(object));
assertEquals([1, 2, 3, object], array.concat(object));
assertEquals([object], Array.prototype.concat.call(object,[]));
assertEquals([object, 1, 2, 3], Array.prototype.concat.call(object, array));
assertEquals([object, object], Array.prototype.concat.call(object, object));
}
testConcatDefaults();
var concatSpreadable = false;
Object.defineProperty(Object.prototype, Symbol.isConcatSpreadable, {
get() { return concatSpreadable },
configurable: true
});
assertEquals([[], array], [].concat(array));
assertEquals([array, []], array.concat([]));
assertEquals([array, array], array.concat(array));
assertEquals([[], object], [].concat(object));
assertEquals([array, object], array.concat(object));
assertEquals([object, []], Array.prototype.concat.call(object,[]));
assertEquals([object, array], Array.prototype.concat.call(object, array));
assertEquals([object, object], Array.prototype.concat.call(object, object));
concatSpreadable = true;
assertEquals(array, [].concat(array));
assertEquals(array, array.concat([]));
assertEquals([1, 2, 3, 1, 2, 3], array.concat(array));
assertEquals(['a'], [].concat(object));
assertEquals([1, 2, 3, 'a'], array.concat(object));
assertEquals(['a'], Array.prototype.concat.call(object,[]));
assertEquals(['a', 1, 2, 3], Array.prototype.concat.call(object, array));
assertEquals(['a', 'a'], Array.prototype.concat.call(object, object));
delete Object.prototype[Symbol.isConcatSpreadable];
testConcatDefaults();
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