fix(ext/node): panic on 'worker_threads.receiveMessageOnPort' (#23386)

Closes https://github.com/denoland/deno/issues/23362

Previously we were panicking if there was a pending read on a
port and `receiveMessageOnPort` was called. This is now fixed
by cancelling the pending read, trying to read a message and
resuming reading in a loop.

1 files changed, 22 insertions, 0 deletions

diff --git a/tests/unit_node/worker_threads_test.ts b/tests/unit_node/worker_threads_test.ts
index 2351e1052..bd600469b 100644
--- a/tests/unit_node/worker_threads_test.ts
+++ b/tests/unit_node/worker_threads_test.ts
@@ -414,3 +414,25 @@ Deno.test({
     mainPort.close();
   },
 });
+
+// Regression test for https://github.com/denoland/deno/issues/23362
+Deno.test("[node/worker_threads] receiveMessageOnPort works if there's pending read", function () {
+  const { port1, port2 } = new workerThreads.MessageChannel();
+
+  const message1 = { hello: "world" };
+  const message2 = { foo: "bar" };
+
+  assertEquals(workerThreads.receiveMessageOnPort(port2), undefined);
+  port2.start();
+
+  port1.postMessage(message1);
+  port1.postMessage(message2);
+  assertEquals(workerThreads.receiveMessageOnPort(port2), {
+    message: message1,
+  });
+  assertEquals(workerThreads.receiveMessageOnPort(port2), {
+    message: message2,
+  });
+  port1.close();
+  port2.close();
+});