time-to-botec

Benchmark sampling in different programming languages
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main.js (1565B)

      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 isFunction = require( './../../is-function' );
     24 var reNativeFunction = require( '@stdlib/regexp/native-function' );
     25 
     26 
     27 // VARIABLES //
     28 
     29 // 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 native function:
     30 var fcn2str = Function.prototype.toString;
     31 
     32 
     33 // MAIN //
     34 
     35 /**
     36 * Tests if a value is a native function.
     37 *
     38 * @param {*} value - value to test
     39 * @returns {boolean} boolean indicating whether value is a native function
     40 *
     41 * @example
     42 * function beep() {
     43 *     console.log( 'boop' );
     44 * }
     45 *
     46 * var bool = isNativeFunction( beep );
     47 * // returns false
     48 *
     49 * bool = isNativeFunction( Date );
     50 * // returns true
     51 */
     52 function isNativeFunction( value ) {
     53 	return (
     54 		isFunction( value ) &&
     55 		reNativeFunction.REGEXP.test( fcn2str.call( value ) )
     56 	);
     57 }
     58 
     59 
     60 // EXPORTS //
     61 
     62 module.exports = isNativeFunction;