main.js (1699B)
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 getOwnPropertyNames = require( './../../property-names' ); 24 var isWritableProperty = require( '@stdlib/assert/is-writable-property' ); 25 26 27 // MAIN // 28 29 /** 30 * Returns an array of an object's own writable property names. 31 * 32 * @param {*} value - input object 33 * @returns {Array} a list of own writable property names 34 * 35 * @example 36 * var defineProperty = require( '@stdlib/utils/define-property' ); 37 * 38 * var obj = { 'a': 'b' }; 39 * 40 * defineProperty( obj, 'beep', { 41 * 'configurable': true, 42 * 'enumerable': true, 43 * 'writable': false, 44 * 'value': 'boop' 45 * }); 46 * 47 * var keys = writablePropertyNames( obj ); 48 * // returns [ 'a' ] 49 */ 50 function writablePropertyNames( value ) { 51 var names; 52 var i; 53 var n; 54 55 if ( value === null || value === void 0 ) { 56 return []; 57 } 58 names = getOwnPropertyNames( Object( value ) ); 59 n = 0; 60 for ( i = 0; i < names.length; i++ ) { 61 if ( isWritableProperty( value, names[ i ] ) ) { 62 names[ n ] = names[ i ]; 63 n += 1; 64 } 65 } 66 names.length = n; 67 68 return names; 69 } 70 71 72 // EXPORTS // 73 74 module.exports = writablePropertyNames;