Add AlarmServer durable object and test

Introduce an AlarmServer Durable Object and test to verify that alarms initialize the DO and call onAlarm without redundant blockConcurrencyWhile. Changes: add AlarmServer class (hibernate:true) with counter and alarmCount, implement onStart/onAlarm/onRequest; export AlarmServer in the test Env; import runDurableObjectAlarm and add a test that schedules an alarm, triggers it via runDurableObjectAlarm, and asserts onStart and alarmCount behavior; register AlarmServer in wrangler.jsonc. This ensures alarm-triggered initialization works as expected.

Author: threepointone

packages/partyserver/src/tests/index.test.ts

@@ -1,6 +1,7 @@
 import {
   createExecutionContext,
-  env
+  env,
+  runDurableObjectAlarm
   // waitOnExecutionContext
 } from "cloudflare:test";
 import { describe, expect, it } from "vitest";
@@ -401,6 +402,43 @@ describe("Hibernating Server (setName handles initialization)", () => {
   });
 });
 
+describe("Alarm (initialize without redundant blockConcurrencyWhile)", () => {
+  it("properly initializes on alarm and calls onAlarm", async () => {
+    // Use a single stub for the entire test so runDurableObjectAlarm
+    // sees the same DO instance that has the alarm scheduled.
+    const id = env.AlarmServer.idFromName("alarm-test1");
+    const stub = env.AlarmServer.get(id);
+
+    // Initialize the DO and schedule an alarm in one request
+    const res = await stub.fetch(
+      new Request(
+        "http://example.com/parties/alarm-server/alarm-test1?setAlarm=1",
+        {
+          headers: { "x-partykit-room": "alarm-test1" }
+        }
+      )
+    );
+    expect(await res.text()).toEqual("alarm set");
+
+    // Trigger the alarm
+    const ran = await runDurableObjectAlarm(stub);
+    expect(ran).toBe(true);
+
+    // Verify state: onStart called once, alarm was triggered once
+    const stateRes = await stub.fetch(
+      new Request("http://example.com/", {
+        headers: { "x-partykit-room": "alarm-test1" }
+      })
+    );
+    const state = (await stateRes.json()) as {
+      counter: number;
+      alarmCount: number;
+    };
+    expect(state.counter).toEqual(1);
+    expect(state.alarmCount).toEqual(1);
+  });
+});
+
 describe("CORS", () => {
   it("returns CORS headers on OPTIONS preflight for matched routes", async () => {
     const ctx = createExecutionContext();

packages/partyserver/src/tests/worker.ts

@@ -12,6 +12,7 @@ export type Env = {
   Stateful: DurableObjectNamespace<Stateful>;
   OnStartServer: DurableObjectNamespace<OnStartServer>;
   HibernatingOnStartServer: DurableObjectNamespace<HibernatingOnStartServer>;
+  AlarmServer: DurableObjectNamespace<AlarmServer>;
   Mixed: DurableObjectNamespace<Mixed>;
   ConfigurableState: DurableObjectNamespace<ConfigurableState>;
   ConfigurableStateInMemory: DurableObjectNamespace<ConfigurableStateInMemory>;
@@ -103,6 +104,40 @@ export class HibernatingOnStartServer extends Server {
   }
 }
 
+/**
+ * Tests that alarm() properly initializes the server
+ * without the redundant blockConcurrencyWhile wrapper.
+ */
+export class AlarmServer extends Server {
+  static options = {
+    hibernate: true
+  };
+
+  counter = 0;
+  alarmCount = 0;
+
+  async onStart() {
+    this.counter++;
+  }
+
+  onAlarm() {
+    this.alarmCount++;
+  }
+
+  async onRequest(request: Request): Promise<Response> {
+    const url = new URL(request.url);
+    if (url.searchParams.get("setAlarm")) {
+      // Schedule alarm far in the future so it won't auto-fire
+      await this.ctx.storage.setAlarm(Date.now() + 60_000);
+      return new Response("alarm set");
+    }
+    return Response.json({
+      counter: this.counter,
+      alarmCount: this.alarmCount
+    });
+  }
+}
+
 export class Mixed extends Server {
   static options = {
     hibernate: true

packages/partyserver/src/tests/wrangler.jsonc

@@ -46,6 +46,10 @@
       {
         "name": "HibernatingOnStartServer",
         "class_name": "HibernatingOnStartServer"
+      },
+      {
+        "name": "AlarmServer",
+        "class_name": "AlarmServer"
       }
     ]
   },
@@ -68,7 +72,7 @@
     },
     {
       "tag": "v4",
-      "new_classes": ["HibernatingOnStartServer"]
+      "new_classes": ["HibernatingOnStartServer", "AlarmServer"]
     }
   ]
 }