63 lines
1.5 KiB
JavaScript
63 lines
1.5 KiB
JavaScript
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/**
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* @license Apache-2.0
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*
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* Copyright (c) 2018 The Stdlib Authors.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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'use strict';
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// MODULES //
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var isFunction = require( './../../is-function' );
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var reNativeFunction = require( '@stdlib/regexp/native-function' );
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// VARIABLES //
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// 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:
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var fcn2str = Function.prototype.toString;
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// MAIN //
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/**
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* Tests if a value is a native function.
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*
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* @param {*} value - value to test
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* @returns {boolean} boolean indicating whether value is a native function
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*
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* @example
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* function beep() {
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* console.log( 'boop' );
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* }
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*
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* var bool = isNativeFunction( beep );
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* // returns false
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*
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* bool = isNativeFunction( Date );
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* // returns true
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*/
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function isNativeFunction( value ) {
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return (
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isFunction( value ) &&
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reNativeFunction.REGEXP.test( fcn2str.call( value ) )
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);
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}
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// EXPORTS //
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module.exports = isNativeFunction;
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