| 'use strict'; |
| |
| var $TypeError = require('es-errors/type'); |
| var isInteger = require('math-intrinsics/isInteger'); |
| |
| var DefinePropertyOrThrow = require('./DefinePropertyOrThrow'); |
| var HasOwnProperty = require('./HasOwnProperty'); |
| var IsExtensible = require('./IsExtensible'); |
| |
| // https://262.ecma-international.org/12.0/#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 (typeof length !== 'number') { |
| throw new $TypeError('Assertion failed: `length` must be a Number'); |
| } |
| if (length !== Infinity && (!isInteger(length) || length < 0)) { |
| throw new $TypeError('Assertion failed: `length` must be ∞, or an integer >= 0'); |
| } |
| return DefinePropertyOrThrow(F, 'length', { |
| '[[Configurable]]': true, |
| '[[Enumerable]]': false, |
| '[[Value]]': length, |
| '[[Writable]]': false |
| }); |
| }; |