JSFiddle - React, Tailwind, and code Playground

JavaScript

function concatArrayBuffers(...bufs){
	const result = new Uint8Array(bufs.reduce((totalSize, buf) => totalSize + buf.byteLength, 0));
	bufs.reduce((offset, buf)=>{
		result.set(buf,offset)
		return offset + buf.byteLength
	}, 0)
	return result.buffer;
}

const a = new Uint8Array(12);
const b = new Uint8Array(14);
const c = new Uint8Array(16);

const res = concatArrayBuffers(a, b, c)

console.log(res.byteLength)