Prerequisites

• I have written a descriptive issue title
• I have searched existing issues to ensure the bug has not already been reported

Fastify version

4

Plugin version

1.1.0

Node.js version

16.17.0

Operating system

Linux

Operating system version (i.e. 20.04, 11.3, 10)

20.04

Description

Since Buffer is in essence just a Uint8Array it gets mangled by deepmerge.

Steps to Reproduce

import { deepmerge } from '@fastify/deepmerge'
const merge = deepmerge()
const merged = JSON.stringify(merge({}, { buffer: Buffer.of(1, 2, 3) })) // {"buffer":{"0":1,"1":2,"2":3}}

Expected Behavior

import { deepmerge } from '@fastify/deepmerge'
const merge = deepmerge()
const merged = JSON.stringify(merge({}, { buffer: Buffer.of(1, 2, 3) })) // {"buffer":{"type":"Buffer","data":[1,2,3]}}