source: imaps-frontend/node_modules/es-abstract/2016/ArraySetLength.js@ d565449

'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;
};