java - mockito junit 中未涵盖接口(interface)中的方法

Question

我正在使用mockito-junit 来测试我的一段代码。随着进展，我发现我正在测试的主文件中实现了一个接口(interface)，当测试运行时，我发现调用接口(interface)方法的行被覆盖，但真正的方法没有被覆盖。

这是主文件的代码:

public class ExtractCurrencyDataTask {

private static final Logger LOGGER = LoggerFactory.getLogger(ExtractCurrencyDataTask.class);

@Autowired
private ExtractCurrencyService extractCurrencyService;

public void writeCurrencyListToFile(List<Currency> currencyList) {
    if (currencyList != null && !currencyList.isEmpty()) {
        String dir = "A path";
        String fileName = "A filename";
        String writeToFile = dir + "/" + fileName + ".writing";
        String renameFile = dir + "/" + fileName + ".dat";

        BufferedWriter writer = null;
        FileWriter fileWriter = null;
        try {
            fileWriter = new FileWriter(writeToFile);
            writer = new BufferedWriter(fileWriter);
            extractCurrencyService.extractCurrencyList(currencyList, writer);
        } catch (Exception e) {
            throw new RuntimeException("Error writing Currency codes", e);
        } finally {
            if (writer != null) {
                try {
                    writer.close();
                    fileWriter.close();
                } catch (IOException e) {
                    LOGGER.info("Exception occured while closing the file writer", e);
                }
                moveFile(writeToFile, renameFile);
            }
        }
    }
}

private void moveFile(String writeToFile, String renameFile) {
    try {
        FileUtils.moveFile(FileUtils.getFile(writeToFile), FileUtils.getFile(renameFile));
    } catch (IOException e) {
        LOGGER.info("Exception occured while moving file from writing to dat", e);
    }
}

这里extractCurrencyService就是我提到的接口(interface)。

界面:

public interface ExtractCurrencyService {

    public void extractCurrencyList(List<Currency> currency, Writer writer);

}

这是由另一个实现相同接口(interface)的文件完成的方法定义 Filename:ExtractCurrencyServiceImpl.java

public class ExtractCurrencyServiceImpl implements ExtractCurrencyService {
    private static final String SEP = "|";
    private static final String NEWLINE = "\n";

@Override
public void extractCurrencyList(List<Currency> currencyList, Writer writer) {
    if (currencyList != null) {
        currencyList.forEach(currency -> {
            String code = currency.getCode();
            String name = currency.getName() == null ? "" : currency.getName();
            Long noOfDecimals = currency.getNumberOfDecimals();
            RoundingMethodValue roundingMethod = currency.getRoundingMethod();
            boolean isDealCurrency = currency.isDealCurrency();
            String description = currency.getDescription() == null ? "" : currency.getDescription();
            try {
                writer.write(createCurrencyDataLine(code,
                                                    name,
                                                    noOfDecimals,
                                                    roundingMethod,
                                                    isDealCurrency,
                                                    description));
            } catch (Exception e) {
                throw new RuntimeException(e);
            }
        });
    }
}

private String createCurrencyDataLine(String code,
                                      String name,
                                      Long noOfDecimals,
                                      RoundingMethodValue roundingMethod,
                                      boolean isdealCurrency,
                                      String description) {
    return code + SEP + name + SEP + noOfDecimals.toString() + SEP + roundingMethod.toString() + SEP
            + isdealCurrency + SEP + description + NEWLINE;
}

public static <T> Predicate<T> distinctByKey(Function<? super T, Object> keyExtractor) {
    Map<Object, Boolean> map = new ConcurrentHashMap<>();
    return t -> map.putIfAbsent(keyExtractor.apply(t), Boolean.TRUE) == null;
}

}

这是测试文件:

@RunWith(MockitoJUnitRunner.class)
public class ExtractCurrencyDataTaskTest {

@Mock
private Currency mockCurrency;

@Mock
private ExtractCurrencyService mockExtractCurrencyService;

@Mock
private BufferedWriter mockBufferWriter;

@Mock
private Bean mockBean;

@InjectMocks
private ExtractCurrencyDataTask extractCurrencyDataTask;

@Test
public void writeCurrencyListToFileTest() {
    List<Currency> currencyList = new ArrayList();
    when(mockCurrency.getCode()).thenReturn("USD");
    when(mockCurrency.getNumberOfDecimals()).thenReturn((long) 2);
    when(mockCurrency.getRoundingMethod()).thenReturn(enum value);
    when(mockCurrency.isDealCurrency()).thenReturn(true);
    when(mockCurrency.getName()).thenReturn("US Dollars");
    when(mockCurrency.getDescription()).thenReturn("Currency Description");
    currencyList.add(mockCurrency);
    extractCurrencyDataTask.writeCurrencyListToFile(currencyList);
}
}

这是 Autowired bean 的配置

@Bean
public ExtractCurrencyService extractCurrencyService() {
    return new ExtractCurrencyServiceImpl();
}

正如您所看到的，此过程的实际输出是在提到的路径中创建一个包含一些数据的文件。在此测试中，我模拟数据并将其传递到主文件。主文件是在各自路径中创建的文件，但文件中没有数据。数据写入部分是通过接口(interface)方法完成的。这是我需要帮助的部分。

提前致谢......

Answer 1

您正在将 ExtractCurrencyService 的模拟注入(inject)到您的测试类中。因此，测试是使用此模拟实例而不是 ExtractCurrencyServiceImpl 运行的。当前的行为是您的 ExtractCurrencyDataTask 测试类正在调用 extractCurrencyService#extractCurrencyList，但此 extractCurrencyService 是一个模拟，而不是您的真正实现，因此调用已完成，但没有执行任何操作。

如果您想对 ExtractCurrencyDataTask 进行单元测试，那么没问题，但也许您应该断言对 extractCurrencyService#extractCurrencyList 的调用已按照您期望的方式完成。

如果您想对 ExtractCurrencyServiceImpl 进行单元测试，请为此类创建一个单元测试。

如果您想测试这两个类之间的交互，请创建一个集成测试，其中 ExtractCurrencyDataTask 注入(inject)了 ExtractCurrencyServiceImpl 的真实实例，而不是模拟。