java - 如何在 Junit 测试中覆盖 catch block ？

Question

我正试图将测试类(class)覆盖到 100%。但是，由于我无法测试 catch block ，所以我最多只能做到 90%。谁能告诉我如何覆盖 catch block 。

下面是我要测试的类:

public class UnsubscribeXmlTransformer {

    public Map<String, Object> process(Map<String, Object> requestMap) {

        String inputStream = requestMap.get(NeoConstants.INPUTSTREAM).toString();

        Smooks smooks;
        try {
            smooks = new Smooks("Unsubscribe-smooks.xml");

            JavaResult javaResult = new JavaResult();


            smooks.filterSource(new StringSource(inputStream), javaResult);


            UnsubscribeDetailsVO unsubscribeDetailsVO = (UnsubscribeDetailsVO) javaResult
                    .getBean("unsubscribeDetailsVO");

            requestMap.put("unsubscribeDetailsVO", unsubscribeDetailsVO);

        } catch (IOException | SAXException e) {        }

        return requestMap;
    }

这是我的测试类:

public class UnsubscribeXmlTransformerTest {
    Map<String, Object> requestMap = null;  

    @Before
    public void prepareRequestMap() {
        requestMap = new HashMap<>();
        String inputStream = "some xml tags";

        requestMap.put(NeoConstants.INPUTSTREAM, inputStream);      
    }


    @Test
    public void processTest() throws Exception {
        UnsubscribeXmlTransformer ref = new UnsubscribeXmlTransformer();
        Map<String, Object> result = ref.process(requestMap);

        Assert.assertNotNull("Result is not null", result);
        Assert.assertFalse("Result is not empty", result.isEmpty());
        Assert.assertTrue("Result contains key named inputStream", result.containsKey(NeoConstants.INPUTSTREAM));
        Assert.assertTrue("Result contains key named unsubscribeDetailsVO", result.containsKey("unsubscribeDetailsVO"));
        Assert.assertTrue("Value with key unsubscribeDetailsVO is an instance of UnsubscribeDetailsVO", result.get("unsubscribeDetailsVO") instanceof UnsubscribeDetailsVO);
    }

    @Test(expected = IOException.class)
    public void processTestForException() {
        UnsubscribeXmlTransformer ref = new UnsubscribeXmlTransformer();

        // how to cover                 
    }
}

Answer 1

您可以在您的 requestMap 上使用 Mockito.spy，并在应该抛出异常时模拟案例。然后(如 jannis 所指出的)您可以使用 AssertJ 的流畅 API 来验证没有抛出异常(您在 catch 子句中将其静音)，例如

@Test
public void process_shouldCatchException() throws Exception{
    UnsubscribeXmlTransformer sut = new UnsubscribeXmlTransformer();
    Map<String, Object> requestMap = Mockito.spy(new HashMap<>());
    when(requestMap.put(eq("unsubscribeDetailsVO"), any()))
        .thenThrow(IOException.class);
    assertThatCode(() -> sut.process(requestMap))
        .doesNotThrowAnyException();
}