cloudfunctions/SegmentPortraitPic/node_modules/isstream/README.md

这里只显示每个文件的开头 60 行。登录后可以解锁完整代码。

微信扫码关注公众号，代码整理好后第一时间通知你。

# isStream

[![Build Status](https://secure.travis-ci.org/rvagg/isstream.png)](http://travis-ci.org/rvagg/isstream)

**Test if an object is a `Stream`**

[![NPM](https://nodei.co/npm/isstream.svg)](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
```