Mocking data classes causes MockKException

[muzzah]

I have a number of data classes and I cannot seem to mock them as they do not have a non arg constructor. Kotlin does not allow this. If I convert it to a normal class then it seems to be able to mock the class.

Im using JUnit 5 with @ExtendWith(MockKExtension::class)

io.mockk.MockKException: No matching constructors found:
constructor(entity : com.google.cloud.datastore.Entity = )
constructor(id : java.util.UUID = , firstName : kotlin.String = , lastName : kotlin.String = , email : kotlin.String = , schoolId : java.util.UUID = , classId : java.util.UUID = , password : kotlin.String = )

at io.mockk.impl.annotations.MockInjector.constructorInjection(MockInjector.kt:20)
at io.mockk.impl.annotations.JvmMockInitializer.doInjection(JvmMockInitializer.kt:62)
at io.mockk.impl.annotations.JvmMockInitializer.initMock(JvmMockInitializer.kt:40)
at io.mockk.impl.annotations.JvmMockInitializer.initAnnotatedMocks(JvmMockInitializer.kt:17)
at io.mockk.junit5.MockKExtension.postProcessTestInstance(MockKExtension.kt:93)
at org.junit.jupiter.engine.descriptor.ClassTestDescriptor.lambda$invokeTestInstancePostProcessors$3(ClassTestDescriptor.java:215)
at org.junit.jupiter.engine.descriptor.JupiterTestDescriptor.executeAndMaskThrowable(JupiterTestDescriptor.java:141)
at org.junit.jupiter.engine.descriptor.ClassTestDescriptor.lambda$invokeTestInstancePostProcessors$4(ClassTestDescriptor.java:215)
at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:193)
at java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:175)
at java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1382)
at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)
at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)
at java.util.stream.StreamSpliterators$WrappingSpliterator.forEachRemaining(StreamSpliterators.java:312)
at java.util.stream.Streams$ConcatSpliterator.forEachRemaining(Streams.java:743)
at java.util.stream.Streams$ConcatSpliterator.forEachRemaining(Streams.java:742)
at java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:580)
at org.junit.jupiter.engine.descriptor.ClassTestDescriptor.invokeTestInstancePostProcessors(ClassTestDescriptor.java:214)
at org.junit.jupiter.engine.descriptor.ClassTestDescriptor.instantiateAndPostProcessTestInstance(ClassTestDescriptor.java:196)
at org.junit.jupiter.engine.descriptor.ClassTestDescriptor.lambda$testInstanceProvider$0(ClassTestDescriptor.java:185)
at org.junit.jupiter.engine.descriptor.ClassTestDescriptor.lambda$testInstanceProvider$1(ClassTestDescriptor.java:189)
at java.util.Optional.orElseGet(Optional.java:267)
at org.junit.jupiter.engine.descriptor.ClassTestDescriptor.lambda$testInstanceProvider$2(ClassTestDescriptor.java:188)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.prepare(TestMethodTestDescriptor.java:81)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.prepare(TestMethodTestDescriptor.java:58)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.prepare(HierarchicalTestExecutor.java:89)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.execute(HierarchicalTestExecutor.java:74)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.lambda$executeRecursively$2(HierarchicalTestExecutor.java:120)
at java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:184)
at java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:175)
at java.util.Iterator.forEachRemaining(Iterator.java:116)
at java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801)
at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)
at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)
at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:151)
at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:174)
at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:418)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.lambda$executeRecursively$3(HierarchicalTestExecutor.java:120)
at org.junit.platform.engine.support.hierarchical.SingleTestExecutor.executeSafely(SingleTestExecutor.java:66)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.executeRecursively(HierarchicalTestExecutor.java:108)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.execute(HierarchicalTestExecutor.java:79)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.lambda$executeRecursively$2(HierarchicalTestExecutor.java:120)
at java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:184)
at java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:175)
at java.util.Iterator.forEachRemaining(Iterator.java:116)
at java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801)
at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)
at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)
at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:151)
at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:174)
at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:418)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.lambda$executeRecursively$3(HierarchicalTestExecutor.java:120)
at org.junit.platform.engine.support.hierarchical.SingleTestExecutor.executeSafely(SingleTestExecutor.java:66)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.executeRecursively(HierarchicalTestExecutor.java:108)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.execute(HierarchicalTestExecutor.java:79)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:55)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:43)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:170)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:154)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:90)
at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:65)
at com.intellij.rt.execution.junit.IdeaTestRunner$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)

[oleksiyp]

Can you minimize code and paste it here. Looks like you are doing @InjectMockK without providing mock for injection.

[muzzah]

Im not sure if this helps but I think it related to trying to mock Optional (which I ended up not doing anyway). For some reason after changing that fact about my test the exception has gone away. Ill close this issue and will come back if I come across anything else.

[oleksiyp]

No issue, no problem 😃 thanks