Question

我有一个异步方法，我正在使用倒计时锁存器转换为同步方法。我在努力编写单元测试而不使用mockito的超时功能。我无法弄清楚如何让验证方法等待异步方法调用：

public interface SyncExchangeService {
    boolean placeOrder(Order order);
}
public interface ExchangeService {
    void placeOrder(Order order, OrderCallback orderResponseCallback);
}

public interface OrderCallback {
    public void onSuccess();
    public void onFailure();
}



public class SyncExchangeServiceAdapter implements SyncExchangeService {
    private ExchangeService exchangeService;

    public SyncExchangeServiceAdapter(ExchangeService exchangeService) {
        this.exchangeService = exchangeService;
    }

    @Override
    public boolean placeOrder(Order order) {

        final CountDownLatch countdownLatch=new CountDownLatch(1);
        final AtomicBoolean result=new AtomicBoolean();
        exchangeService.placeOrder(order, new OrderCallback() {

            @Override
            public void onSuccess() {
                result.set(true);
                countdownLatch.countDown();
            }

            @Override
            public void onFailure(String rejectReason) {
                result.set(false);
                countdownLatch.countDown();
            }
        });
        try {
            countdownLatch.await();
        } catch (InterruptedException e) {
            throw new RuntimeException(e);
        }
        return result.get();
    }
}


public class SyncExchangeServiceAdapterTest {
    private ExchangeService mockExchange=mock(ExchangeService.class);
    private SyncExchangeServiceAdapter adapter=new SyncExchangeServiceAdapter(mockExchange);
    private Boolean response;
    private ArgumentCaptor<Boolean> callback=CaptorArgumentCaptor.forClass(OrderCallback.class);
    private CountDownLatch latch=new CountDownLatch(1);


    @Test
    public void testPlaceOrderWithSuccess() throws Exception {
        final Order order=mock(Order.class);
         Executors.newSingleThreadExecutor().submit(new Runnable() {
            @Override
            public void run() {
                response=adapter.placeOrder(order);
                latch.countDown();
            }
        });
            verify(mockExchange,timeout(10) ).placeOrder(eq(order), callbackCaptor.capture());
//the timeout method is not really recommended and could also fail randomly if the thread takes more than 10ms


        callbackCaptor.getValue().onSuccess();
        latch.await(1000,TimeUnit.MILLISECONDS);
            assertEquals(true,response);
    }


}

Answer 1

对于这些类型的测试，我喜欢使用一个名为awaitility的小库。您可以使用倒计时锁定器自己完成，但正如您所看到的那样，您必须使用弯刀来修复您的测试才能完成这项工作。

在此测试中，您应在等待锁定后调用验证。

代码中的另一个问题是private Boolean response。由于您要在另一个主题中更改它，因此您应该将其设为AtomicBoolean或至少声明为volatile。

Answer 2

我不确定我是否正确理解你。如果你想测试一个线程无限期等待，直到其他线程做某事，那么我会说你不能这样做。因为这意味着你在询问程序是否终止。相反，你可以做两件事。

定期进行并发测试（根据定义，它是随机的，并不能确定代码是否正确）。您使用两个使用锁的线程创建复杂测试并模拟服务并使用yeld（）方法。在关键部分，您可以测试是否没有错误的订单。当然你必须多次运行才能超过10毫秒
假设CountDownLatch正常工作，模拟它并检查其功能是否按正确顺序调用

Mockito与Java async-＆gt;同步转换器

2 个答案: