Question:

I'm using Mockito 2 and Espresso for Unit tests, and met a problem trying to use Mockito 2 in Instrumentation test. While running the test, I'm getting this 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:913)
at $Proxy5.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:232)
at org.mockito.internal.creation.MockSettingsImpl.build(MockSettingsImpl.java:226)
at org.mockito.internal.MockitoCore.mock(MockitoCore.java:64)
at org.mockito.Mockito.mock(Mockito.java:1864)
at org.mockito.Mockito.mock(Mockito.java:1777)
at com.armop.insight.views.activity.InsightActivityTest.testUserResultReturnsEmpty(InsightActivityTest.kt:66)
at java.lang.reflect.Method.invoke(Native Method)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at android.support.test.internal.runner.junit4.statement.RunBefores.evaluate(RunBefores.java:80)
at android.support.test.rule.ActivityTestRule$ActivityStatement.evaluate(ActivityTestRule.java:433)
at org.junit.rules.RunRules.evaluate(RunRules.java:20)
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$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at org.junit.runner.JUnitCore.run(JUnitCore.java:115)
at android.support.test.internal.runner.TestExecutor.execute(TestExecutor.java:58)
at android.support.test.runner.AndroidJUnitRunner.onStart(AndroidJUnitRunner.java:369)
at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:2075)
Caused by: java.lang.IllegalStateException: Failed to load interface org.mockito.plugins.MockMaker implementation declared in sun.misc.CompoundEnumeration@5ea25e5
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.<init>(PluginRegistry.java:21)
at org.mockito.internal.configuration.plugins.Plugins.<clinit>(Plugins.java:18)
at org.mockito.internal.configuration.plugins.Plugins.getMockMaker(Plugins.java:34)
at org.mockito.internal.util.MockUtil.<clinit>(MockUtil.java:24)
... 38 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         : 3.18.91+

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)
... 44 more
Caused by: java.lang.NoClassDefFoundError: Failed resolution of: Ljava/lang/management/ManagementFactory;
at net.bytebuddy.agent.ByteBuddyAgent$ProcessProvider$ForCurrentVm$ForLegacyVm.resolve(ByteBuddyAgent.java:940)
at net.bytebuddy.agent.ByteBuddyAgent$ProcessProvider$ForCurrentVm.resolve(ByteBuddyAgent.java:925)
at net.bytebuddy.agent.ByteBuddyAgent.install(ByteBuddyAgent.java:352)
at net.bytebuddy.agent.ByteBuddyAgent.install(ByteBuddyAgent.java:320)
at net.bytebuddy.agent.ByteBuddyAgent.install(ByteBuddyAgent.java:306)
at org.mockito.internal.creation.bytebuddy.InlineByteBuddyMockMaker.<clinit>(InlineByteBuddyMockMaker.java:101)
... 46 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.armop.debug.test-GWx-9OMGi9FTj01c1acroQ==/base.apk", zip file "/data/app/com.armop.debug-28ywc-fJ-zzWAgMPBESlGQ==/base.apk"],nativeLibraryDirectories=[/data/app/com.armop.debug.test-GWx-9OMGi9FTj01c1acroQ==/lib/x86, /data/app/com.armop.debug-28ywc-fJ-zzWAgMPBESlGQ==/lib/x86, /data/app/com.armop.debug.test-GWx-9OMGi9FTj01c1acroQ==/base.apk!/lib/x86, /data/app/com.armop.debug-28ywc-fJ-zzWAgMPBESlGQ==/base.apk!/lib/x86, /system/lib, /vendor/lib]]
at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:125)
at java.lang.ClassLoader.loadClass(ClassLoader.java:379)
at java.lang.ClassLoader.loadClass(ClassLoader.java:312)
... 52 more

And here is the test code.

 @Test
fun testUserResultReturnsEmpty() {

    val userMock = Mockito.mock(UserModel::class.java)
    Mockito.`when`(ArmOpApplication.getUserFromPrefs()).thenReturn(userMock)

    mActivityRule.launchActivity(Intent())
    mCountDownLatch.await(3000, TimeUnit.MILLISECONDS)

    assertNotNull(mActivityRule.activity.mInsightCategories)

    assertNull(mActivityRule.activity.mData)
    assertNull(mActivityRule.activity.insightsRecyclerView.adapter)
}

I've googled for more information and found out, that I need to use mockito-android instead of mockito core, and added those lines in application's build.gradle file

androidTestImplementation "org.mockito:mockito-android:${libMockitoAndroidVersion}"
androidTestImplementation 'com.linkedin.dexmaker:dexmaker-mockito:2.2.0'

where libMockitoAndroidVersion = 2.16.0

Also, I've added org.mockito.plugins.MockMaker file into the androidTest resource directory to work with Kotlin's classes.

Is there any way to fix this issue? Any help will be appreciated.

Answer:

Working with Android replace

androidTestImplementation "org.mockito:mockito-core:$mockito_core_version"
androidTestImplementation "org.mockito:mockito-inline:$mockito_core_version"

for

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

My version was: $mockito_core_version = '2.28.2'