www.aleph1.co.uk Git - yaffs-website/blob - node_modules/isstream/README.md

   1 # isStream
   2
   3 [![Build Status](https://secure.travis-ci.org/rvagg/isstream.png)](http://travis-ci.org/rvagg/isstream)
   4
   5 **Test if an object is a `Stream`**
   6
   7 [![NPM](https://nodei.co/npm/isstream.svg)](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.