/** * @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 propertyDescriptor = require( '@stdlib/utils/property-descriptor' ); // MAIN // /** * Tests if an object's own property is read-only. * * @param {*} value - value to test * @param {*} property - property to test * @returns {boolean} boolean indicating if an object property is read-only * * @example * var defineProperty = require( '@stdlib/utils/define-property' ); * * var obj = { * 'boop': true * }; * * defineProperty( obj, 'beep', { * 'configurable': false, * 'enumerable': true, * 'writable': false, * 'value': true * }); * * var bool = isReadOnlyProperty( obj, 'boop' ); * // returns false * * bool = isReadOnlyProperty( obj, 'beep' ); * // returns true */ function isReadOnlyProperty( value, property ) { var desc = propertyDescriptor( value, property ); return ( desc !== null && desc.configurable === false && ( // Data descriptor: desc.writable === false || // Accessor descriptor: ( typeof desc.get === 'function' && desc.set === void 0 ) ) ); } // EXPORTS // module.exports = isReadOnlyProperty;