isStream


Test if an object is a Stream


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.

Usage:

``js
var isStream = require('isstream')
var Stream = require('stream')

isStream(new Stream()) // true

isStream({}) // false

isStream(new Stream.Readable()) // true
isStream(new Stream.Writable()) // true
isStream(new Stream.Duplex()) // true
isStream(new Stream.Transform()) // true
isStream(new Stream.PassThrough()) // true
`

But wait! There's more!

You can also test for isReadable(obj), isWritable(obj) and isDuplex(obj) to test for implementations of Streams2 (and Streams3) base classes.

`js
var isReadable = require('isstream').isReadable
var isWritable = require('isstream').isWritable
var isDuplex = require('isstream').isDuplex
var Stream = require('stream')

isReadable(new Stream()) // false
isWritable(new Stream()) // false
isDuplex(new Stream()) // false

isReadable(new Stream.Readable()) // true
isReadable(new Stream.Writable()) // false
isReadable(new Stream.Duplex()) // true
isReadable(new Stream.Transform()) // true
isReadable(new Stream.PassThrough()) // true

isWritable(new Stream.Readable()) // false
isWritable(new Stream.Writable()) // true
isWritable(new Stream.Duplex()) // true
isWritable(new Stream.Transform()) // true
isWritable(new Stream.PassThrough()) // true

isDuplex(new Stream.Readable()) // false
isDuplex(new Stream.Writable()) // false
isDuplex(new Stream.Duplex()) // true
isDuplex(new Stream.Transform()) // true
isDuplex(new Stream.PassThrough()) // true
``

Reminder: when implementing your own streams, please use readable-stream rather than core streams.

License

isStream is Copyright (c) 2015 Rod Vagg @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.