node/test/parallel/test-worker-message-port-transfer-duplicate.js

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

// Test that passing duplicate transferrables in the transfer list throws
// DataCloneError exceptions.

{
  const { port1, port2 } = new MessageChannel();
  port2.once('message', common.mustNotCall());

  const port3 = new MessageChannel().port1;
  assert.throws(() => {
    port1.postMessage(port3, [port3, port3]);
  }, /^DataCloneError: Transfer list contains duplicate MessagePort$/);
  port1.close();
}

{
  const { port1, port2 } = new MessageChannel();
  port2.once('message', common.mustNotCall());

  const buf = new Uint8Array(10);
  assert.throws(() => {
    port1.postMessage(buf, [buf.buffer, buf.buffer]);
  }, /^DataCloneError: Transfer list contains duplicate ArrayBuffer$/);
  port1.close();
}