java.lang.NullPointerException using mock()

[omensight]

Hi, I am working with Mockito and Kotlin, everything works well in AndroidTests, but when I use Mockito on tests, it shows me this message and I don't know how to proceed `"D:\Program Files\Android\Android Studio\jre\bin\java.exe" -ea -Didea.test.cyclic.buffer.size=1048576 "-javaagent:D:\Program Files\Android\Android Studio\lib\idea_rt.jar=62213:D:\Program Files\Android\Android Studio\bin" -Dfile.encoding=UTF-8 -classpath "D:\Program Files\Android\Android Studio\lib\idea_rt.jar" com.intellij.rt.execution.CommandLineWrapper C:\Users\mijae\AppData\Local\Temp\idea_classpath1925221024 com.intellij.rt.junit.JUnitStarter -ideVersion5 -junit4 DataExportBehaviourUnitTest

java.lang.NullPointerException at org.mockito.internal.util.MockCreationValidator.validateType(MockCreationValidator.java:23) at org.mockito.internal.creation.MockSettingsImpl.validatedSettings(MockSettingsImpl.java:238) at org.mockito.internal.creation.MockSettingsImpl.build(MockSettingsImpl.java:226) at org.mockito.internal.MockitoCore.mock(MockitoCore.java:68) at org.mockito.Mockito.mock(Mockito.java:1895) at DataExportBehaviourUnitTest.setUp(DataExportBehaviourUnitTest.kt:35) 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.RunBefores.evaluate(RunBefores.java:24) 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$2.evaluate(ParentRunner.java:268) at org.junit.runners.ParentRunner.run(ParentRunner.java:363) at org.junit.runner.JUnitCore.run(JUnitCore.java:137) at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68) at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33) at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:230) at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:58) 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.CommandLineWrapper.main(CommandLineWrapper.java:64)

Process finished with exit code -1 ` This is the code of the test:

`import com.alphemsoft.education.regression.dataexporter.testfactory.SheetListFactory import com.nhaarman.mockitokotlin2.mock import org.junit.Assert import org.junit.Before import org.junit.Test

class DataExportBehaviourUnitTest { private lateinit var exportBehaviour: ExportBehaviour private val sheetList = SheetListFactory.getRandomList(5)

@Before
fun setUp(){
    exportBehaviour = mock()
}

@Test
fun whenExporting_returnTrue(){
    val export = exportBehaviour.export(sheetList)
    Assert.assertTrue(export)
}

} `

Help please, I am stuck here.

[bohsen]

"D:\Program Files\Android\Android Studio\jre\bin\java.exe" -ea -Didea.test.cyclic.buffer.size=1048576 "-javaagent:D:\Program Files\Android\Android Studio\lib\idea_rt.jar=62213:D:\Program Files\Android\Android Studio\bin" -Dfile.encoding=UTF-8 -classpath "D:\Program Files\Android\Android Studio\lib\idea_rt.jar" com.intellij.rt.execution.CommandLineWrapper C:\Users\mijae\AppData\Local\Temp\idea_classpath1925221024 com.intellij.rt.junit.JUnitStarter -ideVersion5 -junit4 DataExportBehaviourUnitTest

Not sure why the above is shown, but in the test you've shown you never set up your mock. Could you try this:

class DataExportBehaviourUnitTest {
    private val exportBehaviour: ExportBehaviour = mock()
    private val sheetList = SheetListFactory.getRandomList(5)

    @Test
    fun whenExporting_returnTrue() {
        whenever(exportBehavior.export).thenReturn(true)
        val export = exportBehaviour.export(sheetList)
        Assert.assertTrue(export)
    }
}

[omensight]

"D:\Program Files\Android\Android Studio\jre\bin\java.exe" -ea -Didea.test.cyclic.buffer.size=1048576 "-javaagent:D:\Program Files\Android\Android Studio\lib\idea_rt.jar=62213:D:\Program Files\Android\Android Studio\bin" -Dfile.encoding=UTF-8 -classpath "D:\Program Files\Android\Android Studio\lib\idea_rt.jar" com.intellij.rt.execution.CommandLineWrapper C:\Users\mijae\AppData\Local\Temp\idea_classpath1925221024 com.intellij.rt.junit.JUnitStarter -ideVersion5 -junit4 DataExportBehaviourUnitTest

Not sure why the above is shown, but in the test you've shown you never set up your mock. Could you try this:

class DataExportBehaviourUnitTest {
    private val exportBehaviour: ExportBehaviour = mock()
    private val sheetList = SheetListFactory.getRandomList(5)

    @Test
    fun whenExporting_returnTrue() {
        whenever(exportBehavior.export).thenReturn(true)
        val export = exportBehaviour.export(sheetList)
        Assert.assertTrue(export)
    }
}

Thanks for answer. Doing some changes now it gives me another error but don't show me the same message. This happens again only in androidTest not in test. I have created another project to reproduce this error and it is exactly the same as in my original project. When I run the tests it shows me the next error `java.lang.IllegalStateException: Could not initialize plugin: interface org.mockito.plugins.MockMaker (alternate: null) at org.mockito.internal.configuration.plugins.PluginLoader$1.invoke(PluginLoader.java:74) at java.lang.reflect.Proxy.invoke(Proxy.java:1006) at $Proxy4.isTypeMockable(Unknown Source) at org.mockito.internal.util.MockUtil.typeMockabilityOf(MockUtil.java:29) at org.mockito.internal.util.MockCreationValidator.validateType(MockCreationValidator.java:22) at org.mockito.internal.creation.MockSettingsImpl.validatedSettings(MockSettingsImpl.java:238) at org.mockito.internal.creation.MockSettingsImpl.build(MockSettingsImpl.java:226) at org.mockito.internal.MockitoCore.mock(MockitoCore.java:68) at org.mockito.Mockito.mock(Mockito.java:1895) at com.omensight.myapplication.ExampleInstrumentedTest.mocking(ExampleInstrumentedTest.kt:52) at java.lang.reflect.Method.invoke(Native Method) 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.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.mockito.internal.runners.DefaultInternalRunner$1.run(DefaultInternalRunner.java:79) at org.mockito.internal.runners.DefaultInternalRunner.run(DefaultInternalRunner.java:85) at org.mockito.internal.runners.StrictRunner.run(StrictRunner.java:39) at org.mockito.junit.MockitoJUnitRunner.run(MockitoJUnitRunner.java:163) 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$2.evaluate(ParentRunner.java:268) at org.junit.runners.ParentRunner.run(ParentRunner.java:363) at org.junit.runner.JUnitCore.run(JUnitCore.java:137) at org.junit.runner.JUnitCore.run(JUnitCore.java:115) at androidx.test.internal.runner.TestExecutor.execute(TestExecutor.java:56) at androidx.test.runner.AndroidJUnitRunner.onStart(AndroidJUnitRunner.java:395) at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:2204) Caused by: java.lang.IllegalStateException: Failed to load interface org.mockito.plugins.MockMaker implementation declared in sun.misc.CompoundEnumeration@bdd6cf8 at org.mockito.internal.configuration.plugins.PluginInitializer.loadImpl(PluginInitializer.java:54) at org.mockito.internal.configuration.plugins.PluginLoader.loadPlugin(PluginLoader.java:57) at org.mockito.internal.configuration.plugins.PluginLoader.loadPlugin(PluginLoader.java:44) at org.mockito.internal.configuration.plugins.PluginRegistry.(PluginRegistry.java:21) at org.mockito.internal.configuration.plugins.Plugins.(Plugins.java:18) at org.mockito.internal.configuration.plugins.Plugins.getAnnotationEngine(Plugins.java:55) at org.mockito.internal.configuration.GlobalConfiguration.tryGetPluginAnnotationEngine(GlobalConfiguration.java:55) at org.mockito.MockitoAnnotations.initMocks(MockitoAnnotations.java:68) at org.mockito.internal.runners.DefaultInternalRunner$1.withBefores(DefaultInternalRunner.java:39) at org.junit.runners.BlockJUnit4ClassRunner.methodBlock(BlockJUnit4ClassRunner.java:276) ... 25 more Caused by: org.mockito.exceptions.base.MockitoInitializationException: Could not initialize inline Byte Buddy mock maker. (This mock maker is not supported on Android.)

IMPORTANT INFORMATION FOR ANDROID USERS:

The regular Byte Buddy mock makers cannot generate code on an Android VM! To resolve this, please use the 'mockito-android' dependency for your application: http://search.maven.org/#search%7Cga%7C1%7Ca%3A%22mockito-android%22%20g%3A%22org.mockito%22

Java : 0.9 JVM vendor name : The Android Project JVM vendor version : 2.1.0 JVM name : Dalvik JVM version : 0.9 JVM info : null OS name : Linux OS version : 4.14.117-perf-g9f42476

at org.mockito.internal.creation.bytebuddy.InlineByteBuddyMockMaker.<init>(InlineByteBuddyMockMaker.java:171)
at java.lang.Class.newInstance(Native Method)
at org.mockito.internal.configuration.plugins.PluginInitializer.loadImpl(PluginInitializer.java:49)
... 34 more

Caused by: java.lang.NoClassDefFoundError: Failed resolution of: Ljava/lang/management/ManagementFactory; at net.bytebuddy.agent.ByteBuddyAgent$ProcessProvider$ForCurrentVm$ForLegacyVm.resolve(ByteBuddyAgent.java:1038) at net.bytebuddy.agent.ByteBuddyAgent$ProcessProvider$ForCurrentVm.resolve(ByteBuddyAgent.java:1021) at net.bytebuddy.agent.ByteBuddyAgent.install(ByteBuddyAgent.java:358) at net.bytebuddy.agent.ByteBuddyAgent.install(ByteBuddyAgent.java:326) at net.bytebuddy.agent.ByteBuddyAgent.install(ByteBuddyAgent.java:312) at org.mockito.internal.creation.bytebuddy.InlineByteBuddyMockMaker.(InlineByteBuddyMockMaker.java:101) ... 36 more Caused by: java.lang.ClassNotFoundException: Didn't find class "java.lang.management.ManagementFactory" on path: DexPathList[[zip file "/system/framework/android.test.runner.jar", zip file "/system/framework/android.test.mock.jar", zip file "/data/app/com.omensight.myapplication.test-j_LiHE8ECiiqPQjUzR6b5Q==/base.apk", zip file "/data/app/com.omensight.myapplication-NLRWY97zJHBl9O0W5GwxCg==/base.apk"],nativeLibraryDirectories=[/data/app/com.omensight.myapplication.test-j_LiHE8ECiiqPQjUzR6b5Q==/lib/arm64, /data/app/com.omensight.myapplication-NLRWY97zJHBl9O0W5GwxCg==/lib/arm64, /system/lib64, /product/lib64]] at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:196) at java.lang.ClassLoader.loadClass(ClassLoader.java:379) at java.lang.ClassLoader.loadClass(ClassLoader.java:312) ... 42 more And the AndroidTest that I use is the next: @RunWith(MockitoJUnitRunner::class) class ExampleInstrumentedTest { @Test fun useAppContext() { // Context of the app under test. val appContext = InstrumentationRegistry.getInstrumentation().context assertEquals("com.omensight.myapplication", appContext.packageName) }

@Test fun mocking (){ val mock:ISheet = mock() val mock2:ISheet = mock() mock.equals(mock2) verify(mock).equals(any()) } }`

Finally the build.gradle file is: `plugins { id 'com.android.application' id 'kotlin-android' }

android { compileSdkVersion 30 buildToolsVersion "30.0.2"

defaultConfig {
    applicationId "com.omensight.myapplication"
    minSdkVersion 21
    targetSdkVersion 30
    versionCode 1
    versionName "1.0"

    testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
}

buildTypes {
    release {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
    }
}
compileOptions {
    sourceCompatibility JavaVersion.VERSION_1_8
    targetCompatibility JavaVersion.VERSION_1_8
}
kotlinOptions {
    jvmTarget = '1.8'
}

}

dependencies {

implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
implementation 'androidx.core:core-ktx:1.3.2'
implementation 'androidx.appcompat:appcompat:1.2.0'
implementation 'com.google.android.material:material:1.2.1'
implementation 'androidx.constraintlayout:constraintlayout:2.0.4'
testImplementation 'junit:junit:4.+'
androidTestImplementation 'androidx.test.ext:junit:1.1.2'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.3.0'
androidTestImplementation ("androidx.arch.core:core-testing:2.1.0")
testImplementation ("com.nhaarman.mockitokotlin2:mockito-kotlin:2.2.0")
androidTestImplementation ("com.nhaarman.mockitokotlin2:mockito-kotlin:2.2.0")

}`

[bohsen]

IMPORTANT INFORMATION FOR ANDROID USERS: The regular Byte Buddy mock makers cannot generate code on an Android VM!

You're missing a dependency:

androidTestImplementation "org.mockito:mockito-android:$mockito_version"

Looks like your trying to using MockMakerInline in Android instrumentation tests. This wont work.

For Android Instrumentation testing I recommend using fakes. Will save you a lot of headaches.

[chronvas]

This happens in test (not android test) for me too

"C:\Program Files\Android\Android Studio\jre\bin\java.exe" -ea -Didea.test.cyclic.buffer.size=1048576 "-javaagent:C:\Program Files\Android\Android Studio\lib\idea_rt.jar=61748:C:\Program Files\Android\Android Studio\bin" -Dfile.encoding=UTF-8 -classpath C:\Users\User\AppData\Local\Temp\classpath896506186.jar com.intellij.rt.junit.JUnitStarter -ideVersion5 @w@C:\Users\User\AppData\Local\Temp\idea_working_dirs_junit.tmp @C:\Users\User\AppData\Local\Temp\idea_junit.tmp -socket61747

java.lang.IllegalStateException: Could not initialize plugin: interface org.mockito.plugins.MockMaker (alternate: null)