kotlin 和 ArgumentCaptor - IllegalStateException

Question

我在通过 ArgumentCaptor 捕获 Class 参数时遇到问题。我的测试 class 看起来像这样：

@RunWith(RobolectricGradleTestRunner::class)
@Config(sdk = intArrayOf(21), constants = BuildConfig::class)
class MyViewModelTest {
    @Mock
    lateinit var activityHandlerMock: IActivityHandler;

    @Captor
    lateinit var classCaptor: ArgumentCaptor<Class<BaseActivity>>

    @Captor
    lateinit var booleanCaptor: ArgumentCaptor<Boolean>

    private var objectUnderTest: MyViewModel? = null

    @Before
    fun setUp() {
        initMocks(this)
        ...
        objectUnderTest = MyViewModel(...)
    }

    @Test
    fun thatNavigatesToAddListScreenOnAddClicked(){
        //given

        //when
        objectUnderTest?.addNewList()

        //then
        verify(activityHandlerMock).navigateTo(classCaptor.capture(), booleanCaptor.capture())
        var clazz = classCaptor.value
        assertNotNull(clazz);
        assertFalse(booleanCaptor.value);
    }
}

当我运行测试时，抛出以下异常：
java.lang.IllegalStateException: classCaptor.capture() 不能为空
是否可以在 kotlin 中使用参数捕捉器？

========= 更新 1：
科特林：1.0.0-beta-4584
Mockito：1.10.19
Robolectric: 3.0

========= 更新 2：
堆栈跟踪：

java.lang.IllegalStateException: classCaptor.capture() must not be null

at com.example.view.model.ShoplistsViewModelTest.thatNavigatesToAddListScreenOnAddClicked(ShoplistsViewModelTest.kt:92)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.junit.runners.model.FrameworkMethod.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
at org.robolectric.RobolectricTestRunner.evaluate(RobolectricTestRunner.java:251)
at org.robolectric.RobolectricTestRunner.runChild(RobolectricTestRunner.java:188)
at org.robolectric.RobolectricTestRunner.runChild(RobolectricTestRunner.java:54)
at org.junit.runners.ParentRunner.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access[=11=]0(ParentRunner.java:58)
at org.junit.runners.ParentRunner.evaluate(ParentRunner.java:268)
at org.robolectric.RobolectricTestRunner.evaluate(RobolectricTestRunner.java:152)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:69)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:234)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:74)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:144)

Answer 1

classCaptor.capture()的return值为空，但IActivityHandler#navigateTo(Class, Boolean)的签名不允许空参数。

mockito-kotlin库提供了解决这个问题的支持函数。

代码应该是：

    @Captor
    lateinit var classCaptor: ArgumentCaptor<Class<BaseActivity>>

    @Captor
    lateinit var booleanCaptor: ArgumentCaptor<Boolean>

    ...

    @Test
    fun thatNavigatesToAddListScreenOnAddClicked(){
        //given

        //when
        objectUnderTest?.addNewList()

        //then
        verify(activityHandlerMock).navigateTo(
com.nhaarman.mockitokotlin2.capture<Class<BaseActivity>>(classCaptor.capture()), 
com.nhaarman.mockitokotlin2.capture<Boolean>(booleanCaptor.capture())
)
        var clazzValue = classCaptor.value
        assertNotNull(clazzValue);
        val booleanValue = booleanCaptor.value
        assertFalse(booleanValue);
    }

或

var classCaptor = com.nhaarman.mockitokotlin2.argumentCaptor<Class<BaseActivity>>()
var booleanCaptor = com.nhaarman.mockitokotlin2.argumentCaptor<Boolean>()
...
 verify(activityHandlerMock).navigateTo(
classCaptor.capture(), 
booleanCaptor.capture()
)

也在 build.gradle 中添加：

testImplementation "com.nhaarman.mockitokotlin2:mockito-kotlin:2.2.0"

Answer 2

根据我的解决方案：

fun <T> uninitialized(): T = null as T

//open verificator
val verificator = verify(activityHandlerMock)

//capture (would be same with all matchers)
classCaptor.capture()
booleanCaptor.capture()

//hack
verificator.navigateTo(uninitialized(), uninitialized())

Answer 3

由此blog

“让匹配器与 Kotlin 一起工作可能是个问题。如果你有一个用 kotlin 编写的方法，它不接受可为 null 的参数，那么我们无法使用 Mockito.any() 与它匹配。这是因为它可以 return void 并且不能分配给不可为 null 的参数。如果匹配的方法写在 Java 中，那么我认为它将起作用，因为所有 Java 对象都是隐式的可为空。"

需要包装函数 returns ArgumentCaptor.capture() 作为可空类型。

将以下内容作为辅助方法添加到您的测试中

fun <T> capture(argumentCaptor: ArgumentCaptor<T>): T = argumentCaptor.capture()

请参阅 Android 架构库中 Google 提供的 MockitoKotlinHelpers.kt 以供参考。 capture 函数提供了调用 ArgumentCaptor.capture() 的便捷方式。通话

verify(activityHandlerMock).navigateTo(capture(classCaptor), capture(booleanCaptor))

更新：如果上述解决方案不适合您，请在下面的评论中查看 Roberto Leinardi 的解决方案。

Answer 4

在 kotlin-Mockito 库没有帮助后来到这里。我使用反射创建了一个解决方案。它是一个函数，用于提取之前提供给模拟对象的参数：

fun <T: Any, S> getTheArgOfUsedFunctionInMockObject(mockedObject: Any, function: (T) -> S, clsOfArgument: Class<T>): T{
    val argCaptor= ArgumentCaptor.forClass(clsOfArgument)
    val ver = verify(mockedObject)
    argCaptor.capture()
    ver.javaClass.methods.first { it.name == function.reflect()!!.name }.invoke(ver, uninitialized())
    return argCaptor.value
}
private fun <T> uninitialized(): T = null as T

用法：（假设我模拟了我的存储库并测试了一个 viewModel。在使用 MenuObject 对象调用 viewModel 的 "update()" 方法后，我想确保 MenuObject 实际上调用了存储库的 "updateMenuObject()" 方法：

viewModel.update(menuObjectToUpdate)
val arg = getTheArgOfUsedFunctionInMockObject(mockedRepo, mockedRepo::updateMenuObject, MenuObject::class.java)
assertEquals(menuObjectToUpdate, arg)

Answer 5

使用 kotlin-mockito https://mvnrepository.com/artifact/com.nhaarman/mockito-kotlin/1.5.0 作为依赖和示例代码如下：

argumentCaptor<Hotel>().apply {
    verify(hotelSaveService).save(capture())

    assertThat(allValues.size).isEqualTo(1)
    assertThat(firstValue.name).isEqualTo("İstanbul Hotel")
    assertThat(firstValue.totalRoomCount).isEqualTo(10000L)
    assertThat(firstValue.freeRoomCount).isEqualTo(5000L)
}

Answer 6

你可以在参数捕获器上写一个包装器

class CaptorWrapper<T:Any>(private val captor:ArgumentCaptor<T>, private val obj:T){
    fun capture():T{
        captor.capture()
        return obj
    }

    fun captor():ArgumentCaptor<T>{
        return captor
    }
}

Answer 7

如 , you first need to add gradle import for Kotlin-Mockito 所述，然后转移所有导入以使用此库。您的导入现在看起来像：

import com.nhaarman.mockitokotlin2.argumentCaptor
import com.nhaarman.mockitokotlin2.any
import com.nhaarman.mockitokotlin2.eq
import com.nhaarman.mockitokotlin2.isNull
import com.nhaarman.mockitokotlin2.mock
import com.nhaarman.mockitokotlin2.verify

那么你的测试 class 将是这样的：

val mArgumentCaptor = argumentCaptor<SignUpInteractor.Callback>()

@Test
fun signUp_success() {
    val customer = Customer().apply {
        name = "Test Name"
        email = "test@example.com"
        phone = "0123444456789"
        phoneDdi = "+92"
        phoneNumber = ""
        countryCode = "92"
        password = "123456"
    }
    mPresenter.signUp(customer)
    verify(mView).showProgress()
    verify(mInteractor).createAccount(any(), isNull(), mArgumentCaptor.capture())
}

Answer 8

另一种方法：

/**
 * Use instead of ArgumentMatcher.argThat(matcher: ArgumentMatcher<T>)
 */
fun <T> safeArgThat(matcher: ArgumentMatcher<T>): T {
    ThreadSafeMockingProgress.mockingProgress().argumentMatcherStorage
        .reportMatcher(matcher)
    return uninitialized()
}

@Suppress("UNCHECKED_CAST")
private fun <T> uninitialized(): T = null as T

用法：

verify(spiedElement, times(1)).method(
    safeArgThat(
        CustomMatcher()
    )
)

Answer 9

如果 none 所提供的优秀解决方案对您有用，请尝试另一种方法。它基于 Mockito-Kotlin.

[app/build.gradle]
dependencies {
    ...
    testImplementation 'org.mockito.kotlin:mockito-kotlin:3.2.0'
}

在测试文件中定义 Rule 和 Mock。

@RunWith(AndroidJUnit4::class)
class MockitoTest {
    @get:Rule
    val mockitoRule: MockitoRule = MockitoJUnit.rule()

    @Mock
    private lateinit var mockList: MutableList<String>

这是一个例子。

    @Test
    fun `argument captor`() {
        mockList.add("one")
        mockList.add("two")

        argumentCaptor<String>().apply {
            // Verify that "add()" is called twice, and capture the arguments.
            verify(mockList, times(2)).add(capture())

            assertEquals(2, allValues.size)
            assertEquals("one", firstValue)
            assertEquals("two", secondValue)
        }
    }
}

或者，您也可以使用 @Captor。

@Captor
private lateinit var argumentCaptor: ArgumentCaptor<String>

@Test
fun `argument captor`() {
    mockList.add("one")
    mockList.add("two")

    verify(mockList, times(2)).add(capture(argumentCaptor))

    assertEquals(2, argumentCaptor.allValues.size)
    assertEquals("one", argumentCaptor.firstValue)
    assertEquals("two", argumentCaptor.secondValue)
}

kotlin 和 ArgumentCaptor - IllegalStateException

kotlin and ArgumentCaptor - IllegalStateException

android

robolectric

kotlin