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社区首页 >问答首页 >名为验证的Mockito Kotlin单元测试方法抛出空指针异常

问名为验证的Mockito Kotlin单元测试方法抛出空指针异常
EN

Stack Overflow用户
提问于 2018-09-11 18:28:23
回答 4查看 4K关注 0票数 1

每当我尝试验证方法是否被调用时，我都会得到Null Pointer Exception。

代码语言：javascript
运行
复制
class NotesDialogPagePresenterTest {

@Mock
private lateinit var repository: OrderSummaryRepository
@Mock
private lateinit var view: NotesDialogPageContract.View
@Mock
private lateinit var context: Context

private lateinit var presenter: NotesDialogPagePresenter
private val notes = "abcd"
private val remarks = "xyz"


@Before
fun setup() {
    MockitoAnnotations.initMocks(this)
    whenever(view.getContext()).thenReturn(context)
    this.presenter = NotesDialogPagePresenter(view, repository)
}

@Test
fun onCompleteCallClicked_successTest() {

    whenever(repository.updateOrderAfterCompleteCall(notes, remarks)).thenReturn(Completable.complete())

    val spyPresenter = Mockito.spy(presenter)
    spyPresenter.onCompleteCallClicked(notes, remarks)

    verify(view, times(1)).showOnCompleteCallSuccess()
    verify(spyPresenter, times(1)).updateUser()//Null Pointer Exception Here
}

}

演示者类

代码语言：javascript
运行
复制
 class NotesDialogPagePresenter @Inject constructor(var view: NotesDialogPageContract.View,
                                               var repository: OrderSummaryRepository)
: NotesDialogPageContract.Presenter {

private var disposable: Disposable? = null

override fun start() {
}

override fun onCompleteCallClicked(notes: String, remarks: String) {

    disposable = repository.updateOrderAfterCompleteCall(notes, remarks)
            .subscribe({
                view.showOnCompleteCallSuccess()
                updateUser() 
            }, {
                view.showError(it)
            })
}

@VisibleForTesting
internal fun updateUser() {
    disposable = repository.updateUser(-1)
            .subscribe({
                //NO-OP
            }, {
                //NO-OP
            })
}

override fun stop() {
    disposable?.dispose()
}

}

这两个方法需要验证，updateUser()抛出空指针异常

view.showOnCompleteCallSuccess() updateUser()

Logcat：

代码语言：javascript
运行
复制
java.lang.NullPointerException
    at com.rosia.bcp.ordersummary.notes.NotesDialogPagePresenter.updateUser$app_pgDebug(NotesDialogPagePresenter.kt:30)
    at com.rosia.bcp.ordersummary.notes.NotesDialogPagePresenter$onCompleteCallClicked$1.run(NotesDialogPagePresenter.kt:22)
    at io.reactivex.internal.observers.CallbackCompletableObserver.onComplete(CallbackCompletableObserver.java:54)
    at io.reactivex.internal.disposables.EmptyDisposable.complete(EmptyDisposable.java:68)
    at io.reactivex.internal.operators.completable.CompletableEmpty.subscribeActual(CompletableEmpty.java:27)
    at io.reactivex.Completable.subscribe(Completable.java:1794)
    at io.reactivex.Completable.subscribe(Completable.java:1860)
    at com.rosia.bcp.ordersummary.notes.NotesDialogPagePresenter.onCompleteCallClicked(NotesDialogPagePresenter.kt:20)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at com.rosia.bcp.ordersummary.notes.NotesDialogPagePresenter.onCompleteCallClicked(NotesDialogPagePresenter.kt:19)
    at com.rosia.bcp.ordersummary.notes.NotesDialogPagePresenterTest.onCompleteCallClicked_successTest(NotesDialogPagePresenterTest.kt:42)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.junit.runners.model.FrameworkMethod$1.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.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.junit.runners.Suite.runChild(Suite.java:128)
    at org.junit.runners.Suite.runChild(Suite.java:27)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
    at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at com.intellij.rt.execution.application.AppMainV2.main(AppMainV2.java:131)
Exception in thread "main" java.lang.NullPointerException
    at com.rosia.bcp.ordersummary.notes.NotesDialogPagePresenter.updateUser$app_pgDebug(NotesDialogPagePresenter.kt:30)
    at com.rosia.bcp.ordersummary.notes.NotesDialogPagePresenter$onCompleteCallClicked$1.run(NotesDialogPagePresenter.kt:22)
    at io.reactivex.internal.observers.CallbackCompletableObserver.onComplete(CallbackCompletableObserver.java:54)
    at io.reactivex.internal.disposables.EmptyDisposable.complete(EmptyDisposable.java:68)
    at io.reactivex.internal.operators.completable.CompletableEmpty.subscribeActual(CompletableEmpty.java:27)
    at io.reactivex.Completable.subscribe(Completable.java:1794)
    at io.reactivex.Completable.subscribe(Completable.java:1860)
    at com.rosia.bcp.ordersummary.notes.NotesDialogPagePresenter.onCompleteCallClicked(NotesDialogPagePresenter.kt:20)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at com.rosia.bcp.ordersummary.notes.NotesDialogPagePresenter.onCompleteCallClicked(NotesDialogPagePresenter.kt:19)
    at com.rosia.bcp.ordersummary.notes.NotesDialogPagePresenterTest.onCompleteCallClicked_successTest(NotesDialogPagePresenterTest.kt:42)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.junit.runners.model.FrameworkMethod$1.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.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.junit.runners.Suite.runChild(Suite.java:128)
    at org.junit.runners.Suite.runChild(Suite.java:27)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
    at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at com.intellij.rt.execution.application.AppMainV2.main(AppMainV2.java:131)

仅供参考:我使用以下依赖项：

代码语言：javascript
运行
复制
testImplementation 'org.mockito:mockito-core:2.19.0'
testImplementation 'com.squareup.retrofit2:retrofit-mock:2.3.0'
testImplementation 'org.mockito:mockito-inline:2.8.9'
testImplementation 'com.nhaarman:mockito-kotlin-kt1.1:1.6.0'
testImplementation 'junit:junit:4.12'
nullpointerexception
mockito
android
unit-testing
kotlin
EN

Stack Overflow用户

发布于 2019-01-09 02:55:54

如果不想模拟updateUser()的输出，可以实现presenter接口类并验证是否调用了presenterinterface函数。

步骤1:添加presenter接口类

代码语言：javascript
运行
复制
interface INotesDialogPagePresenter {
   fun updateUser()
}

第2步:向演示者实现接口类

代码语言：javascript
运行
复制
class NotesDialogPagePresenter @Inject constructor(var view:NotesDialogPageContract.View,var repository: OrderSummaryRepository)
: NotesDialogPageContract.Presenter,INotesDialogPagePresenter {

private var disposable: Disposable? = null
var implNotesDialogPagePresenter :INotesDialogPagePresenter = this

override fun start() {
}

override fun onCompleteCallClicked(notes: String, remarks: String) {

    disposable = repository.updateOrderAfterCompleteCall(notes, remarks)
            .subscribe({
                view.showOnCompleteCallSuccess()
                implNotesDialogPagePresenter.updateUser() 
            }, {
                view.showError(it)
            })
}

override fun updateUser() {
    disposable = repository.updateUser(-1)
            .subscribe({
                //NO-OP
            }, {
                //NO-OP
            })
}

override fun stop() {
    disposable?.dispose()
}

步骤3:更新测试类(使用mockito-kotlin)

代码语言：javascript
运行
复制
class NotesDialogPagePresenterTest {

val view:NotesDialogPageContract.View= mock()
val repository:OrderSummaryRepository= mock()
val context:Context= mock()
val implNotesDialogPagePresenter :INotesDialogPagePresenter = mock()

private lateinit var presenter: NotesDialogPagePresenter
private val notes = "abcd"
private val remarks = "xyz"


@Before
fun setup() {
    whenever(view.getContext()).thenReturn(context)
    this.presenter = NotesDialogPagePresenter(view, repository)
    presenter.implNotesDialogPagePresenter = implNotesDialogPagePresenter 
}

@Test
fun onCompleteCallClicked_successTest() {

    whenever(repository.updateOrderAfterCompleteCall(notes, remarks)).thenReturn(Completable.complete())

    val spyPresenter = Mockito.spy(presenter)
    spyPresenter.onCompleteCallClicked(notes, remarks)

    verify(view, times(1)).showOnCompleteCallSuccess()
    verify(implNotesDialogPagePresenter , times(1)).updateUser()
}

这样，您实际上不会运行updateUser()，而只是验证被模拟的接口对象是否被调用。这可以防止空指针，并提高测试覆盖率。

票数 1
EN
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页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：

https://stackoverflow.com/questions/52273867

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