66 lines
2.4 KiB
Markdown
66 lines
2.4 KiB
Markdown
# isStream
|
|
|
|
[](http://travis-ci.org/rvagg/isstream)
|
|
|
|
**Test if an object is a `Stream`**
|
|
|
|
[](https://nodei.co/npm/isstream/)
|
|
|
|
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)**.
|
|
|
|
## 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](http://r.va.gg/2014/06/why-i-dont-use-nodes-core-stream-module.html).*
|
|
|
|
|
|
## License
|
|
|
|
**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.
|