Writing Integration Tests

const mockQueue = new MockMessageQueue();

test('message processing integration', async () => {
  await mockQueue.publish('orders', {
    orderId: '123',
    status: 'pending'
  });
  
  await waitForProcessing();
  
  const order = await Order.findById('123');
  expect(order.status).toBe('processed');
  
  const notification = await Notification.findOne({
    orderId: '123'
  });
  expect(notification).toBeDefined();
});