Override variable shows as null in base class for test

[fluxxion82]

The problem looks like if I have a base class with two open variables and I override the variables in an extending class, the variables will show as null in the base class. If there is only one overridden variable, then it appears that there won't be a crash.

I have these classes:

class Bar { fun bhar() = "asdf" }

open class BaseVM( protected open val bar: Bar, ): BaseViewModelCompat() { var inMem: String = bar.bhar() }

class VMUnderTest( override val bar: Bar, ): BaseVM( bar, ) { fun bar(): Boolean = inMem == "asdf" }

and a runable test looks like:

@RunWith(MockitoJUnitRunner::class) class VMUnderTestTest {

@Mock
lateinit var bar: Bar

lateinit var vmUnderTest: VMUnderTest

@Test
fun testSomething() {
    whenever(bar.bhar()).thenReturn("asdf")

    vmUnderTest = VMUnderTest(bar) // npe

    assertTrue(vmUnderTest.bar())
}

}

Exception message only mentions there was a null pointer:

Cannot invoke "com.temp.Bar.bhar()" because the return value of "com.temp.BaseVM.getBar()" is null java.lang.NullPointerException: Cannot invoke "com.temp.Bar.bhar()" because the return value of "com.temp.BaseVM.getBar()" is null at com.temp.BaseVM.(BaseVM.kt:11) at com.temp.VMUnderTest.(VMUnderTest.kt:5) at com.VMUnderTestTest.testSomething(VMUnderTestTest.kt:41) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.base/java.lang.reflect.Method.invoke(Unknown Source) at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:59) at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:56) at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17) at org.mockito.internal.runners.DefaultInternalRunner$1$1.evaluate(DefaultInternalRunner.java:55) at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306) at org.junit.runners.BlockJUnit4ClassRunner$1.evaluate(BlockJUnit4ClassRunner.java:100) at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:366) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:103) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:63) at org.junit.runners.ParentRunner$4.run(ParentRunner.java:331) at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:79) at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:329) at org.junit.runners.ParentRunner.access$100(ParentRunner.java:66) at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:293) at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306) at org.junit.runners.ParentRunner.run(ParentRunner.java:413) at org.mockito.internal.runners.DefaultInternalRunner$1.run(DefaultInternalRunner.java:100) at org.mockito.internal.runners.DefaultInternalRunner.run(DefaultInternalRunner.java:107) at org.mockito.internal.runners.StrictRunner.run(StrictRunner.java:41) at org.mockito.junit.MockitoJUnitRunner.run(MockitoJUnitRunner.java:163) at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecutor.runTestClass(JUnitTestClassExecutor.java:110) at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecutor.execute(JUnitTestClassExecutor.java:58) at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecutor.execute(JUnitTestClassExecutor.java:38) at org.gradle.api.internal.tasks.testing.junit.AbstractJUnitTestClassProcessor.processTestClass(AbstractJUnitTestClassProcessor.java:62) at org.gradle.api.internal.tasks.testing.SuiteTestClassProcessor.processTestClass(SuiteTestClassProcessor.java:51) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.base/java.lang.reflect.Method.invoke(Unknown Source) at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:36) at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24) at org.gradle.internal.dispatch.ContextClassLoaderDispatch.dispatch(ContextClassLoaderDispatch.java:33) at org.gradle.internal.dispatch.ProxyDispatchAdapter$DispatchingInvocationHandler.invoke(ProxyDispatchAdapter.java:94) at jdk.proxy2/jdk.proxy2.$Proxy5.processTestClass(Unknown Source) at org.gradle.api.internal.tasks.testing.worker.TestWorker$2.run(TestWorker.java:176) at org.gradle.api.internal.tasks.testing.worker.TestWorker.executeAndMaintainThreadName(TestWorker.java:129) at org.gradle.api.internal.tasks.testing.worker.TestWorker.execute(TestWorker.java:100) at org.gradle.api.internal.tasks.testing.worker.TestWorker.execute(TestWorker.java:60) at org.gradle.process.internal.worker.child.ActionExecutionWorker.execute(ActionExecutionWorker.java:56) at org.gradle.process.internal.worker.child.SystemApplicationClassLoaderWorker.call(SystemApplicationClassLoaderWorker.java:133) at org.gradle.process.internal.worker.child.SystemApplicationClassLoaderWorker.call(SystemApplicationClassLoaderWorker.java:71) at worker.org.gradle.process.internal.worker.GradleWorkerMain.run(GradleWorkerMain.java:69) at worker.org.gradle.process.internal.worker.GradleWorkerMain.main(GradleWorkerMain.java:74)

other note: if I remove the override in the extending class, I don't get the exception. it seems only if I override the open variable, then i see the issue

versions: mockito: 4.0.0 kotlin: 1.7.10 gradle: 7.5.1 AGP: 7.2.0

running on an M1 mac with Ventura (13.1)