isBuffer

Checks if a value is a Node.js Buffer instance.

Buffer extends Uint8Array and is specific to Node.js, Bun, and Deno. In browser-only environments where Buffer is not defined, this function always returns false.

Useful for filtering or type-narrowing in a functional pipeline: values.filter(isBuffer)

Available since v2.0.0

Import

import { isBuffer } from '@helpers4/node';

Signature

isBuffer(value: unknown): value is Buffer<ArrayBufferLike>

Parameters

Parameter	Type	Description
value	unknown	The value to check

Returns

value is Buffer<ArrayBufferLike> — True if value is a Buffer

Examples

Detect a Node.js Buffer

Returns true only for Buffer instances. Uint8Array is not a Buffer.

isBuffer(Buffer.from('hello')) // => true
isBuffer(new Uint8Array(8))    // => false
isBuffer('hello')              // => false

Filter Buffers from a mixed array

Use as a predicate in .filter() to extract Buffer values.

const values = [Buffer.from('a'), 'text', Buffer.alloc(4), 42];
values.filter(isBuffer)
// => [Buffer, Buffer]

Source

View source on GitHub