Test proxying an RPC stub all the way to Durable Objects. (#122)

* Update dependencies.

* Test proxying an RPC stub all the way to Durable Objects.

In particular, the DO keeps a dup() of the stub and uses it later, after the original subscription call has returned. This requires the `rpc_params_dup_stubs` compat flag, which became default as of 2026-01-20, hence the compat flag update.

Fixes #110.

Author: kentonv

__tests__/test-server-workerd.js

@@ -35,6 +35,15 @@ export class TestDo extends DurableObject {
   getValue() {
     return this.value;
   }
+
+  subscribe(callback) {
+    this.subscriber = callback.dup();
+  }
+
+  async notify(value) {
+    await this.subscriber(value);
+    this.subscriber[Symbol.dispose]();
+  }
 }
 
 export class TestTarget extends RpcTarget {

__tests__/workerd.test.ts

@@ -230,6 +230,9 @@ interface Env {
 interface TestDo extends DurableObject {
   setValue(val: any): void;
   getValue(): any;
+
+  subscribe(callback: (s: string) => void): void;
+  notify(value: string): void;
 }
 
 interface WorkerdTestTarget extends TestTarget {
@@ -268,6 +271,18 @@ describe("workerd RPC server", () => {
       expect(await foo.getValue()).toBe(123);
       expect(await bar.getValue()).toBe("abc");
     }
+
+    {
+      let baz = cap.getDurableObject("baz");
+
+      let receivedValue: any;
+
+      await baz.subscribe((value: any) => {receivedValue = value});
+
+      await baz.notify("hello");
+
+      expect(receivedValue).toBe("hello");
+    }
   })
 
   it("can accept HTTP batch RPC connections", async () => {