worker.onmessage is not called #26856

// main.mjs
import {Worker} from 'worker_threads';

const worker = new Worker("./worker.mjs");
worker.onmessage = ev => console.log("onmessage", ev);
worker.on("message", ev => console.log("EventEmitter", ev));
worker.postMessage("from main to worker")

// worker.mjs
import {parentPort} from 'worker_threads';

parentPort.onmessage = ev => console.log(ev);
parentPort.postMessage("from worker to main");