main.js (1639B)
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 // MAIN // 22 23 /** 24 * Tests if a value is Node stream-like. 25 * 26 * @param {*} value - value to test 27 * @returns {boolean} boolean indicating if a value is Node stream-like 28 * 29 * @example 30 * var transformStream = require( '@stdlib/streams/node/transform' ); 31 * 32 * var stream = transformStream(); 33 * 34 * var bool = isNodeStreamLike( stream ); 35 * // returns true 36 * 37 * bool = isNodeStreamLike( {} ); 38 * // returns false 39 */ 40 function isNodeStreamLike( value ) { 41 return ( 42 // Must be an object: 43 value !== null && 44 typeof value === 'object' && 45 46 // Should be an event emitter: 47 typeof value.on === 'function' && 48 typeof value.once === 'function' && 49 typeof value.emit === 'function' && 50 typeof value.addListener === 'function' && 51 typeof value.removeListener === 'function' && 52 typeof value.removeAllListeners === 'function' && 53 54 // Should have a `pipe` method (Node streams inherit from `Stream`, including writable streams): 55 typeof value.pipe === 'function' 56 ); 57 } 58 59 60 // EXPORTS // 61 62 module.exports = isNodeStreamLike;