biobulkbende.org/node_modules/es-abstract/2018/SetFunctionLength.js
2020-09-16 14:23:28 +02:00

32 lines
1.0 KiB
JavaScript

'use strict';
var GetIntrinsic = require('../GetIntrinsic');
var $TypeError = GetIntrinsic('%TypeError%');
var DefinePropertyOrThrow = require('./DefinePropertyOrThrow');
var HasOwnProperty = require('./HasOwnProperty');
var IsExtensible = require('./IsExtensible');
var ToInteger = require('./ToInteger');
var Type = require('./Type');
// https://ecma-international.org/ecma-262/9.0/#sec-setfunctionlength
module.exports = function SetFunctionLength(F, length) {
if (typeof F !== 'function' || !IsExtensible(F) || HasOwnProperty(F, 'length')) {
throw new $TypeError('Assertion failed: `F` must be an extensible function and lack an own `length` property');
}
if (Type(length) !== 'Number') {
throw new $TypeError('Assertion failed: `length` must be a Number');
}
if (length < 0 || ToInteger(length) !== length) {
throw new $TypeError('Assertion failed: `length` must be an integer >= 0');
}
return DefinePropertyOrThrow(F, 'length', {
'[[Configurable]]': true,
'[[Enumerable]]': false,
'[[Value]]': length,
'[[Writable]]': false
});
};