/** * @license Apache-2.0 * * Copyright (c) 2018 The Stdlib Authors. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ 'use strict'; // MODULES // var getOwnPropertySymbols = require( './../../property-symbols' ); var getPrototypeOf = require( './../../get-prototype-of' ); // FUNCTIONS // /** * Returns a boolean indicating if an array contains a provided value. * * @private * @param {Array} arr - array * @param {*} v - search value * @returns {boolean} boolean indicating if an array contains a search value */ function contains( arr, v ) { var i; for ( i = 0; i < arr.length; i++ ) { if ( arr[ i ] === v ) { return true; } } return false; } // MAIN // /** * Returns an array of an object's own and inherited symbol properties. * * ## Notes * * - In contrast to the built-in `Object.getOwnPropertySymbols()`, this function returns an empty array if provided `undefined` or `null`, rather than throwing an error. * * @param {*} value - input object * @returns {Array} a list of own and inherited symbol properties * * @example * var symbols = propertySymbolsIn( [] ); */ function propertySymbolsIn( value ) { var symbols; var obj; var tmp; var i; if ( value === null || value === void 0 ) { return []; } // Cast the value to an object: obj = Object( value ); // Walk the prototype chain collecting all symbol properties... symbols = []; do { tmp = getOwnPropertySymbols( obj ); for ( i = 0; i < tmp.length; i++ ) { if ( contains( symbols, tmp[ i ] ) === false ) { symbols.push( tmp[ i ] ); } } obj = getPrototypeOf( obj ); } while ( obj ); return symbols; } // EXPORTS // module.exports = propertySymbolsIn;