fix(worker): make cancellation teardown failure-safe

apps/agent-worker/tests/unit/heartbeat-controller.test.ts

@@ -0,0 +1,60 @@
+import { afterEach, beforeEach, describe, expect, test, vi } from 'vitest';
+
+import { createHeartbeatController } from '../../src/heartbeat-controller';
+
+describe('heartbeat controller', () => {
+  beforeEach(() => vi.useFakeTimers());
+  afterEach(() => vi.useRealTimers());
+
+  test('does not overlap ticks while a heartbeat is in flight', async () => {
+    let resolveHeartbeat!: (value: { cancelRequested: boolean }) => void;
+    const heartbeat = vi.fn(
+      () =>
+        new Promise<{ cancelRequested: boolean }>((resolve) => {
+          resolveHeartbeat = resolve;
+        }),
+    );
+    const controller = createHeartbeatController({
+      intervalMs: 30_000,
+      heartbeat,
+      onCancel: vi.fn(),
+      onError: vi.fn(),
+    });
+
+    controller.start('job-1');
+    await vi.advanceTimersByTimeAsync(90_000);
+    expect(heartbeat).toHaveBeenCalledOnce();
+
+    resolveHeartbeat({ cancelRequested: false });
+    await Promise.resolve();
+    await vi.advanceTimersByTimeAsync(30_000);
+    expect(heartbeat).toHaveBeenCalledTimes(2);
+    controller.stop('job-1');
+  });
+
+  test('removes the timer before awaiting cancellation teardown', async () => {
+    let finishCancel!: () => void;
+    const onCancel = vi.fn(
+      () =>
+        new Promise<void>((resolve) => {
+          finishCancel = resolve;
+        }),
+    );
+    const heartbeat = vi.fn().mockResolvedValue({ cancelRequested: true });
+    const controller = createHeartbeatController({
+      intervalMs: 30_000,
+      heartbeat,
+      onCancel,
+      onError: vi.fn(),
+    });
+
+    controller.start('job-1');
+    await vi.advanceTimersByTimeAsync(30_000);
+    expect(onCancel).toHaveBeenCalledOnce();
+    expect(controller.has('job-1')).toBe(false);
+
+    await vi.advanceTimersByTimeAsync(90_000);
+    expect(heartbeat).toHaveBeenCalledOnce();
+    finishCancel();
+  });
+});