| 1 | # isStream
|
|---|
| 2 |
|
|---|
| 3 | [](http://travis-ci.org/rvagg/isstream)
|
|---|
| 4 |
|
|---|
| 5 | **Test if an object is a `Stream`**
|
|---|
| 6 |
|
|---|
| 7 | [](https://nodei.co/npm/isstream/)
|
|---|
| 8 |
|
|---|
| 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)**.
|
|---|
| 10 |
|
|---|
| 11 | ## Usage:
|
|---|
| 12 |
|
|---|
| 13 | ```js
|
|---|
| 14 | var isStream = require('isstream')
|
|---|
| 15 | var Stream = require('stream')
|
|---|
| 16 |
|
|---|
| 17 | isStream(new Stream()) // true
|
|---|
| 18 |
|
|---|
| 19 | isStream({}) // false
|
|---|
| 20 |
|
|---|
| 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
|
|---|
| 26 | ```
|
|---|
| 27 |
|
|---|
| 28 | ## But wait! There's more!
|
|---|
| 29 |
|
|---|
| 30 | You can also test for `isReadable(obj)`, `isWritable(obj)` and `isDuplex(obj)` to test for implementations of Streams2 (and Streams3) base classes.
|
|---|
| 31 |
|
|---|
| 32 | ```js
|
|---|
| 33 | var isReadable = require('isstream').isReadable
|
|---|
| 34 | var isWritable = require('isstream').isWritable
|
|---|
| 35 | var isDuplex = require('isstream').isDuplex
|
|---|
| 36 | var Stream = require('stream')
|
|---|
| 37 |
|
|---|
| 38 | isReadable(new Stream()) // false
|
|---|
| 39 | isWritable(new Stream()) // false
|
|---|
| 40 | isDuplex(new Stream()) // false
|
|---|
| 41 |
|
|---|
| 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
|
|---|
| 47 |
|
|---|
| 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
|
|---|
| 53 |
|
|---|
| 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
|
|---|
| 59 | ```
|
|---|
| 60 |
|
|---|
| 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).*
|
|---|
| 62 |
|
|---|
| 63 |
|
|---|
| 64 | ## License
|
|---|
| 65 |
|
|---|
| 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.
|
|---|
