如何使用 Mockito 模拟内部 class 实例

Question

@ConfigurationProperties(prefix= 'app')
@Getter @Setter
public class AppConfig{
    private ExternalService externalService=new ExternalService();

    @Getter @Setter
    public static class ExternalService{
    private String url;
    private String authToken;
    }
}

我正在使用 AppConfig 的服务。

@Service
@AllArgsConstructor
    public class ExternalService{
    private final AppConfig appConfig;

    public boolean isAuthorize(String token){
        String authUrl=appConfig.getExternalService().getUrl();
        boolean isAuthorize= //External Apis call
        return isAuthorize;
    }
}

测试 class 外部服务

@ExtendWith(MockitoExtension.class)
class ExternalTestService{

    @Mock
    private AppConfig AppConfig;
    
    @Mock
    private AppConfig.ExternalService externalSeriveConfig;

    @InjectMocks
    private ExternalService externalService;

    @Test
    public void shouldAuthorize(){
    //Null Pointer exception for AppConfig.getExternalService() 
    Mockito.when(AppConfig.getExternalService().getUrl()).thenReturn("123456");
    Assertions.assertEquals(externalService.isAuthorize(),true);
}

如果我在 shouldAuthorize 中模拟 GradingProperties.CentralServiceConfig 那么它工作正常但是在 Assertions.assertEquals at ExternalService(String authUrl=appConfig.getExternalService().getUrl();) 时出现 NullPointerException 喜欢

@Test
public void shouldAuthorize(){
    AppConfig.ExternalService externalMock=Mockito.mock(AppConfig.ExternalService.class);
    
    Mockito.when(externalMock.getUrl()).thenReturn("123456");
    Assertions.assertEquals(externalService.isAuthorize(),true);
}

如何模拟并使此代码可运行

Answer 1

当你有链式方法调用时，你需要确保链式调用的每个部分returns非空结果。

Mockito.when(AppConfig.getExternalService().getUrl()).thenReturn("123456");

您还没有对 AppConfig 进行任何调用，因此 AppConfig.getExternalService() returns 无效。

你需要：

Mockito.when(AppConfig.getExternalService()).thenReturn(externalSeriveConfig);
Mockito.when(AppConfig.getExternalService().getUrl()).thenReturn("123456");

或者，甚至更好：

Mockito.when(AppConfig.getExternalService()).thenReturn(externalSeriveConfig);
Mockito.when(externalSeriveConfig.getUrl()).thenReturn("123456");

如何使用 Mockito 模拟内部 class 实例

How to mock Inner class instance using Mockito

junit

mockito

spring-boot

junit5

spring-boot-test