| 'use strict'; |
| |
| var GetIntrinsic = require('get-intrinsic'); |
| var define = require('define-data-property'); |
| var hasDescriptors = require('has-property-descriptors')(); |
| var gOPD = require('gopd'); |
| |
| var $TypeError = require('es-errors/type'); |
| var $floor = GetIntrinsic('%Math.floor%'); |
| |
| /** @type {import('.')} */ |
| module.exports = function setFunctionLength(fn, length) { |
| if (typeof fn !== 'function') { |
| throw new $TypeError('`fn` is not a function'); |
| } |
| if (typeof length !== 'number' || length < 0 || length > 0xFFFFFFFF || $floor(length) !== length) { |
| throw new $TypeError('`length` must be a positive 32-bit integer'); |
| } |
| |
| var loose = arguments.length > 2 && !!arguments[2]; |
| |
| var functionLengthIsConfigurable = true; |
| var functionLengthIsWritable = true; |
| if ('length' in fn && gOPD) { |
| var desc = gOPD(fn, 'length'); |
| if (desc && !desc.configurable) { |
| functionLengthIsConfigurable = false; |
| } |
| if (desc && !desc.writable) { |
| functionLengthIsWritable = false; |
| } |
| } |
| |
| if (functionLengthIsConfigurable || functionLengthIsWritable || !loose) { |
| if (hasDescriptors) { |
| define(/** @type {Parameters<define>[0]} */ (fn), 'length', length, true, true); |
| } else { |
| define(/** @type {Parameters<define>[0]} */ (fn), 'length', length); |
| } |
| } |
| return fn; |
| }; |