如何使用 Mockito 框架模拟我的服务

Question

您好，我正在努力按照下面的方法编写一个模拟测试；

下面是我的代码；

@Component
public class CodeConfigBuilder {

    @Value("${promoConfig.prefix.length}")
    private Integer prefixLength;

    public void validateRequestAndSetDefaults(PromoRequest promoRequest) {
        prefixAndPostFixControlAccordingToLength(promoRequest);
    }

    private void prefixAndPostFixControlAccordingToLength(PromoRequest promoRequest) {
        if (promoRequest.getPostfix() != null) {
            int lengthControl = prefixLength + promoRequest.getPostfix().length();
            if (lengthControl >= promoRequest.getLength()) {
                throw new BadRequestException(Constant.ClientConstants.THE_SUM_OF_PREFIX_AND_POSTFIX_CAN_NOT_BE_GREATER_THAN_LENGHT);
            }
        }    
    }
}

下面是我的yml配置；

 #=========  Promo  Config  ========== #
    
        promoConfig:
          prefix:
            length: 3

下面是我的服务；

public void validateRequest(PromoRequest promoRequest) {
      
        codeConfigBuilder.validateRequestAndSetDefaults(promoRequest);
    }

我创建了一个 PropertySourceResolver 类

@Component
@Getter
public class PropertySourceResolver {
private int prefixLength = 3;

下面还有我的测试课；

@RunWith(MockitoJUnitRunner.class)
class CodeConfigBuilderTest {

   @MockBean
    private PropertySourceResolver propertySourceResolver = new PropertySourceResolver();
    @InjectMocks
    private PromoRequest promoRequest = new PromoRequest();
    @InjectMocks
    private PromoService Service;

   @Before
    public void init() {

        promoRequest.setPrefix("ABC");
        promoRequest.setPostfix("ABCDABCD");
        promoRequest.setQuantity(10);
        promoRequest.setLength(12);
        promoRequest.setCharset("ABCDEF");
    }

    @Test
    public void prefixAndPostFixControl_accordingToLength_for_Succeed() {

        int lengthControl = promoRequest.getPrefix().length() + promoRequest.getPostfix().length();

        if (lengthControl >= promoRequest.getLength()) {
            Assert.assertTrue(false);
        }
    }

我喜欢根据测试场景更改我的代码，例如；当......然后返回任何想法？谢谢。

Answer 1

为了使这更简单和更好地组织您的代码，通过创建以下类来抽象注入配置的复杂性：

@ConfigurationProperties(prefix = "promoConfig.prefix")
public class PromoPrefixConfiguration {
    private Integer length;

    public Integer getLength() {
        return length;
    }
}

然后，您应该将此作为 CodeConfigBuilder 的依赖项：

@Component
public class CodeConfigBuilder {

    private Integer prefixLength;

    public CodeConfigBuilder(PromoPrefixConfiguration promoPrefixConfiguration) {
        this.prefixLength = promoPrefixConfiguration.getLength();
    }

    public void validateRequestAndSetDefaults(PromoRequest promoRequest) {
        prefixAndPostFixControlAccordingToLength(promoRequest);
    }

    private void prefixAndPostFixControlAccordingToLength(PromoRequest promoRequest) {
        if (promoRequest.getPostfix() != null) {
            int lengthControl = prefixLength + promoRequest.getPostfix().length();
            if (lengthControl >= promoRequest.getLength()) {
                throw new BadRequestException(Constant.ClientConstants.THE_SUM_OF_PREFIX_AND_POSTFIX_CAN_NOT_BE_GREATER_THAN_LENGHT);
            }
        }    
    }
}

现在，为了测试这个类，您必须进行三个测试：

1. 测试PromoRequest 是否有效，因为postfix 为空；
2. 测试PromoRequest是否有效，因为长度有效；
3. 测试PromoRequest无效，因为长度无效；

它们将类似于以下内容：

class CodeConfigBuilderTest {

    private PromoPrefixConfiguration promoPrefixConfiguration = new PromoPrefixConfiguration(10);
    private CodeConfigBuilder codeConfigBuilder = new CodeConfigBuilder(promoPrefixConfiguration);

    @Test
    public void promoRequestIsValidGivenNullPostfix() {
        // Arrange
        PromoRequest promoRequest = new PromoRequest();
        promoRequest.setPostfix(null);

        // Act
        codeConfigBuilder.validateRequestAndSetDefaults(promoRequest);
    }

    @Test
    public void promoRequestIsValidGivenValidPrefixPlusPostfixLength() {
        // Arrange
        PromoRequest promoRequest = new PromoRequest();
        promoRequest.setPostfix("ABCD");
        promoRequest.setLength(15);

        // Act
        codeConfigBuilder.validateRequestAndSetDefaults(promoRequest);
    }

    @Test(expected = BadRequestException.class)
    public void promoRequestIsInvalidGivenInvalidPrefixPlusPostfixLength() {
        // Arrange
        PromoRequest promoRequest = new PromoRequest();
        promoRequest.setPostfix("ABCDEFGH");
        promoRequest.setLength(15);

        // Act
        codeConfigBuilder.validateRequestAndSetDefaults(promoRequest);
    }
}

如果您使用的是 JUnit 5，则可以将最后一个测试替换为以下测试，以轻松断言异常消息：

@Test
public void promoRequestIsInvalidGivenInvalidPrefixPlusPostfixLength() {
    // Arrange
    PromoRequest promoRequest = new PromoRequest();
    promoRequest.setPrefix("ABCDEFG");
    promoRequest.setPostfix("HIJKLMN");

    // Act 
    Exception exception = assertThrows(BadRequestException.class, () -> {
        codeConfigBuilder.validateRequestAndSetDefaults(promoRequest);
    });

    // Assert
    String exceptionMessage = exception.getMessage();
    assertTrue(exceptionMessage.equals(Constant.ClientConstants.THE_SUM_OF_PREFIX_AND_POSTFIX_CAN_NOT_BE_GREATER_THAN_LENGHT));
}

P.S.：你的意思是 suffix 而不是 postfix？