@yuhere/js-buffer

Forked from feross/buffer — rewritten in TypeScript with modern ESM tooling.

The buffer module from Node.js, for the browser — backed by Uint8Array.

Fork notice

This is a TypeScript port of feross/buffer by Feross Aboukhadijeh.

Key changes from the original:

• Rewritten in TypeScript with full type declarations
• Build tooling migrated to Vite (Rollup-powered ESM output)
• Test framework migrated from Mocha/Chai to Vitest
• Published as @yuhere/js-buffer (ESM only)

Install

npm install @yuhere/js-buffer

Usage

import { Buffer } from '@yuhere/js-buffer'

const buf = new Buffer('hello', 'utf8')
console.log(buf.toString('hex'))   // 68656c6c6f
console.log(buf.toString('base64')) // aGVsbG8=

API

The API is 100% identical to Node.js's Buffer API. Read the official Node.js docs for the full list of supported methods.

Features

• Backed by Typed Arrays (Uint8Array / ArrayBuffer) — fast and memory-efficient
• Preserves Node.js Buffer API exactly
• .slice() returns instances of the same type (Buffer)
• Square-bracket buf[4] notation works everywhere
• Does not modify any browser prototypes

Important differences

Always use Buffer.isBuffer, not instanceof Buffer

The Buffer constructor returns an augmented Uint8Array for performance, so instanceof Buffer won't work. Always use Buffer.isBuffer(b) to check.

buf.slice() and shared memory

In Node.js, slice() creates a new Buffer that shares memory with the original. This works correctly in modern browsers with typed array support. Very old browsers (Firefox < 30) use an alternate Object-based implementation where slices don't share memory.

How it works

Buffer extends Uint8Array, adding all Node.js Buffer methods as properties on each instance. This gives us square-bracket indexing and fast typed-array operations without touching Uint8Array.prototype.

Development

npm install
npm test              # Run Node tests
npm run test:browser  # Run browser tests (Playwright)
npm run test:coverage # Combined Node + Browser coverage
npm run build         # Build ESM output to lib/

License

MIT. Copyright (C) Feross Aboukhadijeh, and other contributors. Originally forked from an MIT-licensed module by Romain Beauxis.