kotlin：使用模拟注入的单元测试（mockK）

Question

class SWServiceImplTest {

    @MockK
    lateinit var externalApi: ExternalApiService

    @InjectMockKs
    lateinit var SWService: SWServiceImpl

    @Before
    fun setUp() = MockKAnnotations.init(this)

    @Test
    fun SWCharacterReturnsCorrectValues() {

        every { externalApi.get<Characters>(Utils.SW_API) } returns mockCharacters()

        val result = SWService.swCharacter!!
        assertEquals("blue", result.first().color?.toLowerCase())
        assertEquals(result.size, 3)
    }

}

15:09:54.497 [main] DEBUG io.mockk.impl.instantiation.AbstractMockFactory - Creating mockk for <error "java.lang.NoClassDefFoundError: kotlin/coroutines/intrinsics/IntrinsicsKt"> name=externalApi#1
15:09:56.820 [main] DEBUG org.springframework.web.client.RestTemplate - HTTP GET https://xxx.xxx/
15:09:57.038 [main] DEBUG org.springframework.web.client.RestTemplate - Accept=[application/json, application/*+json]

org.springframework.web.client.RestClientException: No HttpMessageConverter for java.lang.Object and content type ""

    companion object{
        val api = ExternalApiService()
    }

我的实现出了什么问题？谢谢

Answer 1

Kotlin为companion对象{}生成一个名为companion的内部类。这个companion类将只有声明的字段的getter（在您的例子中是getapi())。但是该字段由外部类SWService维护。

因此SWService的等效java类看起来像。

public final class SWService {
   private static final ExternalApiService api = new ExternalApiService();

   public static final class Companion() {
       public final ExternalApiService getApi() {
          return SWService.api;
       }
   }
}

现在要模拟API，这是static字段。这可以使用PowerMockito完成。

testImplementation "org.powermock:powermock-api-mockito2:2.0.0-beta.5"

public final class SWServiceTest {

   @MockK
   lateinit var api: ExternalApiService

   var service = SWService()

    @Before
    fun setUp() {
        MockKAnnotations.init(this)
        Whitebox.setInternalState(SWService::class.java,"api", api);
    }
}