This would also help to quickly upload/download things using (node-)fetch and do other things with it

I think that it would be awesome to "transition" node-canvas to be an implementation of OffscreenCanvas instead of Canvas, which is more accurately what it is current anyways. Maybe even change import { createCanvas } from 'canvas' to import { OffscreenCanvas } from 'canvas' (but keep the old function as well for compatibility)?

Anything that makes us more compatible I'm 👍

(but keep the old function as well for compatibility)?

yea, sounds good!
but OffscreenCanvas is a constructor doe... need to use new

ctx.drawImage would have to accept a ImageBitmap class instead/also, But it maybe already do? saw some stuff in the readme that i missed and that u have util like createBitmap

fyi, fetch-blob is a ESM only package, so to load it from commonjs you would have to use the async import() instead cuz esm are async b/c of top level await

but that would be fine either way. createImageBitmap don't need to import something to know that it's a blob and can be read.
convertToBlob is async either way also. so can just lazy import it when needed instead

(but keep the old function as well for compatibility)?

yea, sounds good!
but OffscreenCanvas is a constructor doe...

Yeah, we could export an OffscreenCanvas class and have createCanvas return new OffscreenCanvas(...)

fyi, fetch-blob is a ESM only package

With the next major canvas version I think we should go ESM only as well

Maybe this is a good boilerplate to start of from:

import { Bitmap } from './bindings.js'
const unlock = Symbol('Illegal constructor')

class ImageBitmap {
  #width = 0
  #height = 0
  #close

  constructor(key, width, height, #close) {
    if (key !== unlock) {
      throw new Error('Illegal constructor')
    }
  }

  get width () {
    return this.#width
  }

  get height () {
    return this.#height
  }

  close() {
    this.#close && this.#close()
    this.#close = null
  }
}

const registry = new FinalizationRegistry(bitmap => {
  bitmap.close()
});

/**
 * @param {Blob} image
 */
async function createImageBitmap(image, sx, sy, sw, sh, options = {}) {
  const ab = await blob.arrayBuffer()
  const data = new Bitmap(new Uint8Array(ab))
  const imageBitmap = new ImageBitmap(unlock, data.width, data.height, data.close.bind(data))
  registry.register(imageBitmap, data)
  return imageBitmap
}

is .toBlob gonna be implemented..?

b/c node-canvas is more like a OffscreenCanvas then i have already made a PR that adds the async convertToBlob