isstream
Advanced tools
Package description
The isstream npm package is a simple utility to check if an object is a stream. It provides functions to determine if an object is a readable, writable, or duplex stream.
Check if an object is a stream
This feature allows you to check if a given object is a stream. In this example, we use the fs module to create a readable stream and then check if it is a stream using isStream.
const isStream = require('isstream');
const fs = require('fs');
const readableStream = fs.createReadStream('example.txt');
console.log(isStream(readableStream)); // trueCheck if an object is a readable stream
This feature allows you to check if a given object is a readable stream. In this example, we use the fs module to create a readable stream and then check if it is a readable stream using isStream.isReadable.
const isStream = require('isstream');
const fs = require('fs');
const readableStream = fs.createReadStream('example.txt');
console.log(isStream.isReadable(readableStream)); // trueCheck if an object is a writable stream
This feature allows you to check if a given object is a writable stream. In this example, we use the fs module to create a writable stream and then check if it is a writable stream using isStream.isWritable.
const isStream = require('isstream');
const fs = require('fs');
const writableStream = fs.createWriteStream('example.txt');
console.log(isStream.isWritable(writableStream)); // trueCheck if an object is a duplex stream
This feature allows you to check if a given object is a duplex stream. In this example, we create a duplex stream using the stream module and then check if it is a duplex stream using isStream.isDuplex.
const isStream = require('isstream');
const { Duplex } = require('stream');
const duplexStream = new Duplex();
console.log(isStream.isDuplex(duplexStream)); // trueThe is-stream package provides similar functionality to isstream, allowing you to check if an object is a stream, readable stream, writable stream, or duplex stream. It is a lightweight and straightforward alternative.
The stream package is part of Node.js core and provides a comprehensive API for working with streams. While it does not provide simple type-checking functions like isstream, it offers extensive functionality for creating and managing streams.
The through2 package is a tiny wrapper around Node.js streams2 Transform to avoid explicit subclassing noise. It is more focused on stream transformation but can be used in conjunction with isstream for type-checking.
Readme
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.
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
You can also test for isReadable(obj), isWritable(obj) and isDuplex(obj) to test for implementations of Streams2 (and Streams3) base classes.
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.
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.
FAQs
Determine if an object is a Stream
We found that isstream demonstrated a not healthy version release cadence and project activity because the last version was released a year ago. It has 1 open source maintainer collaborating on the project.
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