Constnium/node_modules/es-abstract/2015/ArraySetLength.js
2022-06-23 02:27:43 +02:00

85 lines
2.6 KiB
JavaScript

'use strict';
var GetIntrinsic = require('get-intrinsic');
var $RangeError = GetIntrinsic('%RangeError%');
var $TypeError = GetIntrinsic('%TypeError%');
var assign = require('object.assign');
var isPropertyDescriptor = require('../helpers/isPropertyDescriptor');
var IsArray = require('./IsArray');
var IsAccessorDescriptor = require('./IsAccessorDescriptor');
var IsDataDescriptor = require('./IsDataDescriptor');
var OrdinaryDefineOwnProperty = require('./OrdinaryDefineOwnProperty');
var OrdinaryGetOwnProperty = require('./OrdinaryGetOwnProperty');
var ToNumber = require('./ToNumber');
var ToString = require('./ToString');
var ToUint32 = require('./ToUint32');
var Type = require('./Type');
// https://ecma-international.org/ecma-262/6.0/#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({
Type: Type,
IsDataDescriptor: IsDataDescriptor,
IsAccessorDescriptor: IsAccessorDescriptor
}, 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;
};