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node_modules/es-abstract/2017/ArraySetLength.js
| 85 lines
| 2.6 KiB
| application/javascript
| JavascriptLexer
|
| r789 | 'use strict'; | |||
| var GetIntrinsic = require('../GetIntrinsic'); | ||||
| 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://www.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; | ||||
| }; | ||||