3 [![Build Status](https://secure.travis-ci.org/rvagg/isstream.png)](http://travis-ci.org/rvagg/isstream)
5 **Test if an object is a `Stream`**
7 [![NPM](https://nodei.co/npm/isstream.svg)](https://nodei.co/npm/isstream/)
9 The missing `Stream.isStream(obj)`: determine if an object is standard Node.js `Stream`. Works for Node-core `Stream` objects (for 0.8, 0.10, 0.11, and in theory, older and newer versions) and all versions of **[readable-stream](https://github.com/isaacs/readable-stream)**.
14 var isStream = require('isstream')
15 var Stream = require('stream')
17 isStream(new Stream()) // true
21 isStream(new Stream.Readable()) // true
22 isStream(new Stream.Writable()) // true
23 isStream(new Stream.Duplex()) // true
24 isStream(new Stream.Transform()) // true
25 isStream(new Stream.PassThrough()) // true
28 ## But wait! There's more!
30 You can also test for `isReadable(obj)`, `isWritable(obj)` and `isDuplex(obj)` to test for implementations of Streams2 (and Streams3) base classes.
33 var isReadable = require('isstream').isReadable
34 var isWritable = require('isstream').isWritable
35 var isDuplex = require('isstream').isDuplex
36 var Stream = require('stream')
38 isReadable(new Stream()) // false
39 isWritable(new Stream()) // false
40 isDuplex(new Stream()) // false
42 isReadable(new Stream.Readable()) // true
43 isReadable(new Stream.Writable()) // false
44 isReadable(new Stream.Duplex()) // true
45 isReadable(new Stream.Transform()) // true
46 isReadable(new Stream.PassThrough()) // true
48 isWritable(new Stream.Readable()) // false
49 isWritable(new Stream.Writable()) // true
50 isWritable(new Stream.Duplex()) // true
51 isWritable(new Stream.Transform()) // true
52 isWritable(new Stream.PassThrough()) // true
54 isDuplex(new Stream.Readable()) // false
55 isDuplex(new Stream.Writable()) // false
56 isDuplex(new Stream.Duplex()) // true
57 isDuplex(new Stream.Transform()) // true
58 isDuplex(new Stream.PassThrough()) // true
61 *Reminder: when implementing your own streams, please [use **readable-stream** rather than core streams](http://r.va.gg/2014/06/why-i-dont-use-nodes-core-stream-module.html).*
66 **isStream** is Copyright (c) 2015 Rod Vagg [@rvagg](https://twitter.com/rvagg) and licenced under the MIT licence. All rights not explicitly granted in the MIT license are reserved. See the included LICENSE.md file for more details.