Bug: worker_threads missing MessagePort conversion in deeply nested object

[marvinhagemeister]

Passing a MesssagePort instance via postMessage inside a deeply nested object is not converted to a node MessagePort.

Steps to reproduce

1. Create a file worker.mjs with these contents:

import process from "node:process";
import { parentPort } from "node:worker_threads";

parentPort.on("message", (ev) => {
  console.assert(
    typeof ev.foo.bar.addListener === "function",
    "MessagePort doesn't have 'addListener' method"
  );
  process.exit(0);
});

2. Create a file main.mjs with these contents:

import { Worker, MessageChannel } from "node:worker_threads";

const w = new Worker("./worker.mjs");

const port = new MessageChannel().port1;
w.postMessage({ foo: { bar: port } }, [port]);

3. Run deno run -A main.mjs

Version: Deno 1.43.3