polyfill.js (1697B)
1 /** 2 * @license Apache-2.0 3 * 4 * Copyright (c) 2018 The Stdlib Authors. 5 * 6 * Licensed under the Apache License, Version 2.0 (the "License"); 7 * you may not use this file except in compliance with the License. 8 * You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, software 13 * distributed under the License is distributed on an "AS IS" BASIS, 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 * See the License for the specific language governing permissions and 16 * limitations under the License. 17 */ 18 19 'use strict'; 20 21 // MODULES // 22 23 var hasOwnProp = require( './../../has-own-property' ); 24 var isEnumerableProperty = require( './../../is-enumerable-property' ); 25 var isArray = require( './../../is-array' ); 26 var isInteger = require( '@stdlib/math/base/assert/is-integer' ); 27 var MAX_LENGTH = require( '@stdlib/constants/uint32/max' ); 28 29 30 // MAIN // 31 32 /** 33 * Tests whether a value is an `arguments` object. 34 * 35 * @private 36 * @param {*} value - value to test 37 * @returns {boolean} boolean indicating whether a value is an `arguments` object 38 * 39 * @example 40 * function foo() { 41 * return arguments; 42 * } 43 * 44 * var bool = isArguments( foo() ); 45 * // returns true 46 * 47 * @example 48 * var bool = isArguments( [] ); 49 * // returns false 50 */ 51 function isArguments( value ) { 52 return ( 53 value !== null && 54 typeof value === 'object' && 55 !isArray( value ) && 56 typeof value.length === 'number' && 57 isInteger( value.length ) && 58 value.length >= 0 && 59 value.length <= MAX_LENGTH && 60 hasOwnProp( value, 'callee' ) && 61 !isEnumerableProperty( value, 'callee' ) 62 ); 63 } 64 65 66 // EXPORTS // 67 68 module.exports = isArguments;