78 lines
2.4 KiB
JavaScript
78 lines
2.4 KiB
JavaScript
|
'use strict';
|
||
|
|
|
||
|
|
var $RangeError = require('es-errors/range');
|
||
|
|
var $TypeError = require('es-errors/type');
|
||
|
|
|
||
|
|
var assign = require('object.assign');
|
||
|
|
|
||
|
|
var isPropertyDescriptor = require('../helpers/records/property-descriptor');
|
||
|
|
|
||
|
|
var IsArray = require('./IsArray');
|
||
|
|
var IsDataDescriptor = require('./IsDataDescriptor');
|
||
|
|
var OrdinaryDefineOwnProperty = require('./OrdinaryDefineOwnProperty');
|
||
|
|
var OrdinaryGetOwnProperty = require('./OrdinaryGetOwnProperty');
|
||
|
|
var ToNumber = require('./ToNumber');
|
||
|
|
var ToString = require('./ToString');
|
||
|
|
var ToUint32 = require('./ToUint32');
|
||
|
|
|
||
|
|
// https://262.ecma-international.org/6.0/#sec-arraysetlength
|
||
|
|
|
||
|
|
// eslint-disable-next-line max-statements, max-lines-per-function
|
||
|
|
module.exports = function ArraySetLength(A, Desc) {
|
||
|
|
if (!IsArray(A)) {
|
||
|
|
throw new $TypeError('Assertion failed: A must be an Array');
|
||
|
|
}
|
||
|
|
if (!isPropertyDescriptor(Desc)) {
|
||
|
|
throw new $TypeError('Assertion failed: Desc must be a Property Descriptor');
|
||
|
|
}
|
||
|
|
if (!('[[Value]]' in Desc)) {
|
||
|
|
return OrdinaryDefineOwnProperty(A, 'length', Desc);
|
||
|
|
}
|
||
|
|
var newLenDesc = assign({}, Desc);
|
||
|
|
var newLen = ToUint32(Desc['[[Value]]']);
|
||
|
|
var numberLen = ToNumber(Desc['[[Value]]']);
|
||
|
|
if (newLen !== numberLen) {
|
||
|
|
throw new $RangeError('Invalid array length');
|
||
|
|
}
|
||
|
|
newLenDesc['[[Value]]'] = newLen;
|
||
|
|
var oldLenDesc = OrdinaryGetOwnProperty(A, 'length');
|
||
|
|
if (!IsDataDescriptor(oldLenDesc)) {
|
||
|
|
throw new $TypeError('Assertion failed: an array had a non-data descriptor on `length`');
|
||
|
|
}
|
||
|
|
var oldLen = oldLenDesc['[[Value]]'];
|
||
|
|
if (newLen >= oldLen) {
|
||
|
|
return OrdinaryDefineOwnProperty(A, 'length', newLenDesc);
|
||
|
|
}
|
||
|
|
if (!oldLenDesc['[[Writable]]']) {
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
var newWritable;
|
||
|
|
if (!('[[Writable]]' in newLenDesc) || newLenDesc['[[Writable]]']) {
|
||
|
|
newWritable = true;
|
||
|
|
} else {
|
||
|
|
newWritable = false;
|
||
|
|
newLenDesc['[[Writable]]'] = true;
|
||
|
|
}
|
||
|
|
var succeeded = OrdinaryDefineOwnProperty(A, 'length', newLenDesc);
|
||
|
|
if (!succeeded) {
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
while (newLen < oldLen) {
|
||
|
|
oldLen -= 1;
|
||
|
|
// eslint-disable-next-line no-param-reassign
|
||
|
|
var deleteSucceeded = delete A[ToString(oldLen)];
|
||
|
|
if (!deleteSucceeded) {
|
||
|
|
newLenDesc['[[Value]]'] = oldLen + 1;
|
||
|
|
if (!newWritable) {
|
||
|
|
newLenDesc['[[Writable]]'] = false;
|
||
|
|
OrdinaryDefineOwnProperty(A, 'length', newLenDesc);
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
if (!newWritable) {
|
||
|
|
return OrdinaryDefineOwnProperty(A, 'length', { '[[Writable]]': false });
|
||
|
|
}
|
||
|
|
return true;
|
||
|
|
};
|