/** * @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 MAX_SAFE_INTEGER = require( '@stdlib/constants/float64/max-safe-integer' ); var isPositiveInteger = require( '@stdlib/assert/is-positive-integer' ).isPrimitive; var propertySymbols = require( './../../property-symbols' ); var propertyNames = require( './../../property-names' ); 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 inherited property names and symbols. * * @param {*} value - input object * @param {PositiveInteger} [level] - inheritance level * @throws {TypeError} second argument must be a positive integer * @returns {Array} a list of inherited property names and symbols * * @example * var props = inheritedProperties( [] ); * // returns [...] */ function inheritedProperties( value, level ) { var out; var obj; var tmp; var N; var n; var i; if ( arguments.length > 1 ) { if ( !isPositiveInteger( level ) ) { throw new TypeError( 'invalid argument. Second argument must be a positive integer. Value: `' + level + '`.' ); } N = level; } else { N = MAX_SAFE_INTEGER; } if ( value === null || value === void 0 ) { return []; } // Get the value's prototype: obj = getPrototypeOf( value ); // Walk the prototype chain collecting all properties... out = []; n = 1; while ( obj && n <= N ) { tmp = propertyNames( obj ); for ( i = 0; i < tmp.length; i++ ) { if ( contains( out, tmp[ i ] ) === false ) { out.push( tmp[ i ] ); } } tmp = propertySymbols( obj ); for ( i = 0; i < tmp.length; i++ ) { if ( contains( out, tmp[ i ] ) === false ) { out.push( tmp[ i ] ); } } obj = getPrototypeOf( obj ); n += 1; } return out; } // EXPORTS // module.exports = inheritedProperties;