/** * @license Apache-2.0 * * Copyright (c) 2021 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 isFunction = require( './../../is-function' ); // VARIABLES // var RE_CLASS = /^\s*class\s/; // Using `Function#toString` bypasses a value's own `toString` method to provide an extra, but not security proof, precaution to prevent a provided function from impersonating a class: var fcn2str = Function.prototype.toString; // MAIN // /** * Tests if a value is a class. * * @param {*} value - value to test * @returns {boolean} boolean indicating whether value is a class * * @example * var bool = isClass( class Person {} ); * // returns true * * @example * var bool = isClass( function Person() {} ); * // returns false * * @example * var bool = isClass( null ); * // returns false */ function isClass( value ) { var str; if ( !isFunction( value ) ) { return false; } str = fcn2str.call( value ); return RE_CLASS.test( str ); } // EXPORTS // module.exports = isClass;