worker: throw for duplicates in transfer list

Throw a `DataCloneError` exception when encountering duplicate
`ArrayBuffer`s or `MessagePort`s in the transfer list.

Fixes: https://github.com/nodejs/node/issues/25786

PR-URL: https://github.com/nodejs/node/pull/25815
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>

1 files changed, 29 insertions, 0 deletions

diff --git a/test/parallel/test-worker-message-port-transfer-duplicate.js b/test/parallel/test-worker-message-port-transfer-duplicate.js
new file mode 100644
index 0000000000..c893556d8d
--- /dev/null
+++ b/test/parallel/test-worker-message-port-transfer-duplicate.js
@@ -0,0 +1,29 @@
+'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();
+}