worker lifecycle port test

test/js/node/worker_threads/worker-lifecycle-message-port.test.ts

@@ -0,0 +1,49 @@
+import assert from "node:assert";
+import { test } from "node:test";
+import { fileURLToPath } from "node:url";
+import { isMainThread, MessageChannel, MessagePort, parentPort, Worker } from "node:worker_threads";
+
+interface StartupMessage {
+  port: MessagePort;
+}
+
+if (isMainThread) {
+  test("worker lifecycle message port", async () => {
+    const worker = new Worker(fileURLToPath(import.meta.url));
+
+    const { port1, port2 } = new MessageChannel();
+
+    const { promise, resolve, reject } = Promise.withResolvers<string>();
+
+    port1.on("message", (message: string) => {
+      console.log("Received message:", message);
+      assert.equal(message, "hello");
+      worker.terminate();
+      resolve(message);
+    });
+
+    worker.on("online", () => {
+      console.log("Worker is online");
+      const startupMessage: StartupMessage = { port: port2 };
+      worker.postMessage(startupMessage, [port2]);
+    });
+
+    worker.on("exit", () => {
+      console.log("Worker exited");
+      reject();
+    });
+
+    worker.on("error", err => {
+      reject(err);
+    });
+
+    assert.equal(await promise, "hello");
+  });
+} else {
+  parentPort!.on("message", (message: StartupMessage) => {
+    console.log("Worker received startup message");
+
+    message.port.postMessage("hello");
+    message.port.close();
+  });
+}