模擬嘗試初始化字段

Question

我有一個類，我試圖模擬並在其上調用一個方法-

@Component open class CloudStorageService {
  @Autowired lateinit var s3Client: AmazonS3

    fun getSizeOfFirstMatchedObject(bucketName: String, directory: String, prefix: String): Long {
    val request = ListObjectsRequest().withBucketName(bucketName).withPrefix("$directory/$prefix")
    val listObjects = s3Client.listObjects(request)
    val objectSummary = listObjects.objectSummaries.first()
    val size = objectSummary.size
    return size / (1024 * 1024)
  }
}

我在另一個類中使用這種方法 -

@Service
open class SizingService(private val cloudStorageService: CloudStorageService) {
 fun methodName() {
   ...
   val fileSize = cloudStorageService.getSizeOfFirstMatchedObject("bucketName", "filename", "prefix") // trying to mock this call
   ...
 }
}

我的測試文件：

@ActiveProfiles("test")
@RunWith(SpringRunner::class)
@SpringBootTest(classes = [TestAppConfig::class])
class SizingServiceTest {
  @Mock private lateinit var cloudStorageService: CloudStorageService

  @Before
  fun setUp() {
    MockitoAnnotations.openMocks(this)
    sizingService = SizingService(cloudStorageService)
  }
  
  @Test
  fun shouldReturnDropletSizeForChainBusinessesCorrectly() {
    `when`(cloudStorageService.getSizeOfFirstMatchedObject(eq("b1")!!, eq("filename"), eq(prefix))).thenReturn(200)
  }
}

s3Client 在我的 AppConfig 中被初始化為 bean -

@Configuration
@EnableTransactionManagement
@EnableScheduling
open class AppConfig {
  
  @Value("\${S3_REGION}") lateinit var awsRegion: String
  @Value("\${S3_ACCESS_KEY}") lateinit var accessKey: String
  @Value("\${S3_SECRET_KEY}") lateinit var secretKey: String
  
    @Bean(name = ["s3Client"])
  open fun s3Client(): AmazonS3 {
    return AmazonS3ClientBuilder.standard().withRegion(awsRegion).withCredentials(AWSStaticCredentialsProvider(BasicAWSCredentials(accessKey, secretKey))).build()
  }
}

但是當我運行測試時，我得到一個失敗，說 s3Client 未初始化。 為什么當它是一個 mock 時，它甚至試圖在CloudStorageService中初始化 s3Client ？

lateinit property s3Client has not been initialized
kotlin.UninitializedPropertyAccessException: lateinit property s3Client has not been initialized
    at com.service.CloudStorageService.getS3Client(CloudStorageService.kt:33)
    at com.service.CloudStorageService.getSizeOfFirstMatchedObject(CloudStorageService.kt:113)
    at com.service.SizingServiceTest.shouldReturnDropletSizeForChainBusinessesCorrectly(SizingServiceTest.kt:219)

如何正確模擬此方法？

Answer 1

我使我正在模擬的方法open並且模擬工作。 但我不知道為什么如果方法未打開，mockito 會嘗試初始化。 錯誤消息也沒有幫助。

有人可以解釋 mockito 實際在做什么以及方法的open性如何允許模擬發生嗎？

// Only Change I did was adding `open`.
open fun getSizeOfFirstMatchedObject(bucketName: String, directory: String, prefix: String): Long {
    val request = ListObjectsRequest().withBucketName(bucketName).withPrefix("$directory/$prefix")
    val listObjects = s3Client.listObjects(request)
    val objectSummary = listObjects.objectSummaries.first()
    val size = objectSummary.size
    return size / (1024 * 1024)
  }