is-stream

Functions

• isDuplexStream()
• isReadableStream()
• isStream()
• isTransformStream()
• isWritableStream()

Type Aliases

• Options

function isDuplexStream

isDuplexStream: (stream: unknown, options?: Options) => stream is DuplexStream;

• Returns

  Whether stream is a [stream.Duplex](https://nodejs.org/api/stream.html#stream_class_stream_duplex).

  Example 1

  import {Duplex as DuplexStream} from 'node:stream';
  import {isDuplexStream} from 'is-stream';
  
  isDuplexStream(new DuplexStream());
  //=> true

function isReadableStream

isReadableStream: (
    stream: unknown,
    options?: Options
) => stream is ReadableStream;

• Returns

  Whether stream is a [stream.Readable](https://nodejs.org/api/stream.html#stream_class_stream_readable) or an [http.IncomingMessage](https://nodejs.org/api/http.html#class-httpincomingmessage).

  Example 1

  import fs from 'node:fs';
  import {isReadableStream} from 'is-stream';
  
  isReadableStream(fs.createReadStream('unicorn.png'));
  //=> true

function isStream

isStream: (stream: unknown, options?: Options) => stream is Stream;

• Returns

  Whether stream is a [Stream](https://nodejs.org/api/stream.html#stream_stream).

  Example 1

  import fs from 'node:fs';
  import {isStream} from 'is-stream';
  
  isStream(fs.createReadStream('unicorn.png'));
  //=> true
  
  isStream({});
  //=> false

function isTransformStream

isTransformStream: (
    stream: unknown,
    options?: Options
) => stream is TransformStream;

• Returns

  Whether stream is a [stream.Transform](https://nodejs.org/api/stream.html#stream_class_stream_transform).

  Example 1

  import fs from 'node:fs';
  import StringifyStream from 'streaming-json-stringify';
  import {isTransformStream} from 'is-stream';
  
  isTransformStream(StringifyStream());
  //=> true

function isWritableStream

isWritableStream: (
    stream: unknown,
    options?: Options
) => stream is WritableStream;

• Returns

  Whether stream is a [stream.Writable](https://nodejs.org/api/stream.html#stream_class_stream_writable), an [http.OutgoingMessage](https://nodejs.org/api/http.html#class-httpoutgoingmessage), an [http.ServerResponse](https://nodejs.org/api/http.html#class-httpserverresponse) or an [http.ClientRequest](https://nodejs.org/api/http.html#class-httpserverresponse).

  Example 1

  import fs from 'node:fs';
  import {isWritableStream} from 'is-stream';
  
  isWritableStream(fs.createWriteStrem('unicorn.txt'));
  //=> true

type Options

type Options = {
    /**
	When this option is `true`, the method returns `false` if the stream has already been closed.

	@default true
	*/
    checkOpen?: boolean;
};