test/parallel/test-worker-mjs-workerdata.js

'use strict';
const common = require('../common');
const fixtures = require('../common/fixtures');
const assert = require('assert');
const { Worker } = require('worker_threads');

const workerData = 'Hello from main thread';

const worker = new Worker(fixtures.path('worker-data.mjs'), {
  workerData,
  execArgv: ['--experimental-modules']
});

worker.on('message', common.mustCall((message) => {
  assert.strictEqual(message, workerData);
}));