test.js

/* eslint-disable no-underscore-dangle */
'use strict';

// MODULES //

var stream = require( 'stream' );
var EventEmitter = require( 'events' ).EventEmitter;
var tape = require( 'tape' );
var transformStream = require( '@stdlib/streams/utils/transform' );
var isNodeDuplexStreamLike = require( './../lib' );


// TESTS //

tape( 'main export is a function', function test( t ) {
	t.ok( true, __filename );
	t.strictEqual( typeof isNodeDuplexStreamLike, 'function', 'main export is a function' );
	t.end();
});

tape( 'the function returns `true` if provided a value which is Node duplex stream-like', function test( t ) {
	var values;
	var s;
	var i;

	function pipe() {
		// pipe function
	}

	function read() {
		// read function
	}

	function write() {
		// write function
	}

	s = new EventEmitter();
	s.pipe = pipe;
	s._read = read;
	s._write = write;
	s._readableState = {};
	s._writableState = {};

	values = [
		new stream.Transform(),
		new stream.Duplex(),
		transformStream(),
		s
	];

	for ( i = 0; i < values.length; i++ ) {
		t.strictEqual( isNodeDuplexStreamLike( values[ i ] ), true, 'returns true for value '+i );
	}
	t.end();
});

tape( 'the function returns `false` if  not provided a value which is Node duplex stream-like', function test( t ) {
	var values;
	var i;

	values = [
		'5',
		5,
		NaN,
		true,
		false,
		null,
		undefined,
		[],
		{},
		function pipe() {},
		new EventEmitter(),
		new stream.Writable(),
		new stream.Readable(),
		new stream.Stream()
	];

	for ( i = 0; i < values.length; i++ ) {
		t.strictEqual( isNodeDuplexStreamLike( values[ i ] ), false, 'returns false when provided '+values[ i ] );
	}
	t.end();
});