Node.js can't create Blobs?

The Solution to this problem is to create a function which can convert between Array Buffers and Node Buffers. :)

Convert a binary NodeJS Buffer to JavaScript ArrayBuffer

In recent node versions it's just:

let buffer = Buffer.from(arraybuffer);
let arraybuffer = Uint8Array.from(buffer).buffer;

Just use cross-blob:

const Blob = require("cross-blob");

new Blob([]);
//=> Blob {size: 0, type: ""}

// Global patch (to support external modules like is-blob).
globalThis.Blob = Blob;