fix: Benchmarks that use timers cannot use workers.

examples/worker-threads/node.js

@@ -11,4 +11,12 @@ suite
   .add('Using import with node: prefix', function () {
     return import('node:fs');
   })
+	.add('async test', async function (timer) {
+		timer.start();
+		let i = 0;
+		while (i++ < timer.count) {
+			await import("node:fs");
+		}
+		timer.end(timer.count);
+	})
   .run();

lib/worker-runner.js

@@ -1,9 +1,17 @@
 const { parentPort } = require("node:worker_threads");
 const { runBenchmark } = require("./lifecycle");
+const AsyncFunction = Object.getPrototypeOf(async () => {}).constructor;
 
 // Deserialize the benchmark function
 function deserializeBenchmark(benchmark) {
-	benchmark.fn = new Function(benchmark.fn);
+	const { isAsync, hasArg } = benchmark;
+	const fnPrototype = isAsync ? AsyncFunction : Function;
+
+	if (hasArg) {
+		benchmark.fn = new fnPrototype("timer", benchmark.fn);
+	} else {
+		benchmark.fn = new fnPrototype(benchmark.fn);
+	}
 }
 
 parentPort.on(

test/worker.js

@@ -21,15 +21,27 @@ describe("Using worker_threads", () => {
 			})
 			.add("Import without node: prefix", () => {
 				return import("node:fs");
+			})
+			.add("async test", async () => {
+				return import("node:fs");
+			})
+			.add("async with timer", async (timer) => {
+				timer.start();
+				let i = 0;
+				while (i++ < timer.count) {
+					await import("node:fs");
+				}
+				timer.end(timer.count);
 			});
+
 		await bench.run();
 	});
 
 	after(() => {
 		mock.restoreAll();
 	});
 
-	it("should create a new Worker 2 times", () => {
-		assert.strictEqual(workerThreads.Worker.mock.calls.length, 2);
+	it("should create a new Worker 4 times", () => {
+		assert.strictEqual(workerThreads.Worker.mock.calls.length, 4);
 	});
 });