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// Copyright (C) 2018 Leo Balter. All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.
/*---
esid: sec-array.prototype.flatMap
description: >
Does not flatten array-like objects nested into the main array
info: |
FlattenIntoArray(target, source, sourceLen, start, depth [ , mapperFunction, thisArg ])
1. Let targetIndex be start.
2. Let sourceIndex be 0.
3. Repeat, while sourceIndex < sourceLen
a. Let P be ! ToString(sourceIndex).
b. Let exists be ? HasProperty(source, P).
c. If exists is true, then
i. Let element be ? Get(source, P).
ii. If mapperFunction is present, then
1. Assert: thisArg is present.
2. Set element to ? Call(mapperFunction, thisArg , « element, sourceIndex, source »).
iii. Let shouldFlatten be false.
iv. If depth > 0, then
1. Set shouldFlatten to ? IsArray(element).
v. If shouldFlatten is true, then
1. Let elementLen be ? ToLength(? Get(element, "length")).
2. Set targetIndex to ? FlattenIntoArray(target, element, elementLen, targetIndex, depth - 1).
vi. Else,
1. If targetIndex ≥ 253-1, throw a TypeError exception.
2. Perform ? CreateDataPropertyOrThrow(target, ! ToString(targetIndex), element).
3. Increase targetIndex by 1.
includes: [compareArray.js]
features: [Array.prototype.flatMap, Int32Array]
---*/
function fn(e) {
return e;
}
var obj1 = {
length: 1,
0: 'a',
toString() { return 'obj1'; }
};
var obj2 = new Int32Array(2);
var obj3 = {
get length() { throw "should not even consider the length property" },
toString() { return 'obj3'; }
};
var arr = [obj1, obj2, obj3];
var actual = arr.flatMap(fn);
assert.compareArray(actual, arr, 'The value of actual is expected to equal the value of arr');
assert.notSameValue(actual, arr, 'The value of actual is expected to not equal the value of `arr`');
var arrLike = {
length: 4,
0: obj1,
1: obj2,
2: obj3,
get 3() { return arrLike },
toString() { return 'obj4'; }
};
actual = [].flatMap.call(arrLike, fn);
assert.compareArray(actual, [obj1, obj2, obj3, arrLike], 'The value of actual is expected to be [obj1, obj2, obj3, arrLike]');
assert.notSameValue(actual, arrLike, 'The value of actual is expected to not equal the value of `arrLike`');
assert.sameValue(
Object.getPrototypeOf(actual),
Array.prototype,
'Object.getPrototypeOf([].flatMap.call(arrLike, fn)") returns Array.prototype'
);
reportCompare(0, 0);
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