fix: prevent duplicate cron runs across hot reloads

src/cron/service.prevents-duplicate-timers.test.ts

@@ -0,0 +1,89 @@
+import fs from "node:fs/promises";
+import os from "node:os";
+import path from "node:path";
+
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+
+import { CronService } from "./service.js";
+
+const noopLogger = {
+  debug: vi.fn(),
+  info: vi.fn(),
+  warn: vi.fn(),
+  error: vi.fn(),
+};
+
+async function makeStorePath() {
+  const dir = await fs.mkdtemp(path.join(os.tmpdir(), "clawdbot-cron-"));
+  return {
+    storePath: path.join(dir, "cron", "jobs.json"),
+    cleanup: async () => {
+      await fs.rm(dir, { recursive: true, force: true });
+    },
+  };
+}
+
+describe("CronService", () => {
+  beforeEach(() => {
+    vi.useFakeTimers();
+    vi.setSystemTime(new Date("2025-12-13T00:00:00.000Z"));
+    noopLogger.debug.mockClear();
+    noopLogger.info.mockClear();
+    noopLogger.warn.mockClear();
+    noopLogger.error.mockClear();
+  });
+
+  afterEach(() => {
+    vi.useRealTimers();
+  });
+
+  it("avoids duplicate runs when two services share a store", async () => {
+    const store = await makeStorePath();
+    const enqueueSystemEvent = vi.fn();
+    const requestHeartbeatNow = vi.fn();
+    const runIsolatedAgentJob = vi.fn(async () => ({ status: "ok" }));
+
+    const cronA = new CronService({
+      storePath: store.storePath,
+      cronEnabled: true,
+      log: noopLogger,
+      enqueueSystemEvent,
+      requestHeartbeatNow,
+      runIsolatedAgentJob,
+    });
+
+    await cronA.start();
+    const atMs = Date.parse("2025-12-13T00:00:01.000Z");
+    await cronA.add({
+      name: "shared store job",
+      enabled: true,
+      schedule: { kind: "at", atMs },
+      sessionTarget: "main",
+      wakeMode: "next-heartbeat",
+      payload: { kind: "systemEvent", text: "hello" },
+    });
+
+    const cronB = new CronService({
+      storePath: store.storePath,
+      cronEnabled: true,
+      log: noopLogger,
+      enqueueSystemEvent,
+      requestHeartbeatNow,
+      runIsolatedAgentJob,
+    });
+
+    await cronB.start();
+
+    vi.setSystemTime(new Date("2025-12-13T00:00:01.000Z"));
+    await vi.runOnlyPendingTimersAsync();
+    await cronA.status();
+    await cronB.status();
+
+    expect(enqueueSystemEvent).toHaveBeenCalledTimes(1);
+    expect(requestHeartbeatNow).toHaveBeenCalledTimes(1);
+
+    cronA.stop();
+    cronB.stop();
+    await store.cleanup();
+  });
+});