fix start delay on Worker (#3707)

* fix start delay on Worker

* fmt

* add delay test

3 files changed, 30 insertions, 0 deletions

diff --git a/test/js/third_party/comlink/comlink.test.ts b/test/js/third_party/comlink/comlink.test.ts
new file mode 100644
index 000000000..77d810950
--- /dev/null
+++ b/test/js/third_party/comlink/comlink.test.ts
@@ -0,0 +1,15 @@
+import { test, expect, describe } from "bun:test";
+import { join } from "path";
+import * as Comlink from "comlink";
+
+describe("comlink", () => {
+  test("should start without big delay", async () => {
+    const worker = new Worker(join(import.meta.dir, "worker.fixture.ts"));
+    const obj = Comlink.wrap(worker);
+    const start = performance.now();
+    //@ts-ignore
+    await obj.counter;
+    const end = performance.now();
+    expect(end - start).toBeLessThan(100);
+  });
+});
diff --git a/test/js/third_party/comlink/package.json b/test/js/third_party/comlink/package.json
new file mode 100644
index 000000000..707196be3
--- /dev/null
+++ b/test/js/third_party/comlink/package.json
@@ -0,0 +1,6 @@
+{
+  "name": "comlink",
+  "dependencies": {
+    "comlink": "4.4.1"
+  }
+}
diff --git a/test/js/third_party/comlink/worker.fixture.ts b/test/js/third_party/comlink/worker.fixture.ts
new file mode 100644
index 000000000..1cfcfbe9f
--- /dev/null
+++ b/test/js/third_party/comlink/worker.fixture.ts
@@ -0,0 +1,9 @@
+import * as Comlink from "comlink";
+const obj = {
+  counter: 0,
+  inc() {
+    this.counter++;
+  },
+};
+
+Comlink.expose(obj);