Using a kotlin closure for `custom` step no longer works in Gradle plugin

[cmuchinsky]

• [x] summary of problem

Using a kotlin closure for custom step no longer works in Gradle plugin

• [x] Gradle or Maven version

Gradle 8.12

• [x] spotless version

7.0.0 and 7.0.1

• [x] operating system and version

Mac/latest

• [x] copy-paste your full Spotless configuration block(s), and a link to a public git repo that reproduces the problem if possible

java {
    custom("Refuse wildcard imports") {
        if (it.contains("*;\n")) {
            throw GradleException("No wildcard imports allowed.")
        }
        it
    }
}

• [x] copy-paste the full content of any console errors emitted by gradlew spotless[Apply/Check] --stacktrace

> Task :spotlessJava FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':spotlessJava'.
> java.io.NotSerializableException: REDACTED

* Try:
> Run with --info or --debug option to get more log output.
> Get more help at https://help.gradle.org.

* Exception is:
org.gradle.api.tasks.TaskExecutionException: Execution failed for task ':spotlessJava'.
        at org.gradle.api.internal.tasks.execution.CatchExceptionTaskExecuter.execute(CatchExceptionTaskExecuter.java:38)
        at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.executeTask(EventFiringTaskExecuter.java:77)
        at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.call(EventFiringTaskExecuter.java:55)
        at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.call(EventFiringTaskExecuter.java:52)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:209)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:204)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$2.execute(DefaultBuildOperationRunner.java:66)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$2.execute(DefaultBuildOperationRunner.java:59)
        at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:166)
        at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:59)
        at org.gradle.internal.operations.DefaultBuildOperationRunner.call(DefaultBuildOperationRunner.java:53)
        at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter.execute(EventFiringTaskExecuter.java:52)
        at org.gradle.execution.plan.LocalTaskNodeExecutor.execute(LocalTaskNodeExecutor.java:42)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$InvokeNodeExecutorsAction.execute(DefaultTaskExecutionGraph.java:331)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$InvokeNodeExecutorsAction.execute(DefaultTaskExecutionGraph.java:318)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.lambda$execute$0(DefaultTaskExecutionGraph.java:314)
        at org.gradle.internal.operations.CurrentBuildOperationRef.with(CurrentBuildOperationRef.java:85)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.execute(DefaultTaskExecutionGraph.java:314)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.execute(DefaultTaskExecutionGraph.java:303)
        at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.execute(DefaultPlanExecutor.java:459)
        at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.run(DefaultPlanExecutor.java:376)
        at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:64)
        at org.gradle.internal.concurrent.AbstractManagedExecutor$1.run(AbstractManagedExecutor.java:48)
Caused by: com.diffplug.spotless.ThrowingEx$WrappedAsRuntimeException: java.io.NotSerializableException: Spotless_init_gradle$1$1$2$1$1$1
        at com.diffplug.spotless.ThrowingEx.asRuntime(ThrowingEx.java:95)
        at com.diffplug.spotless.LazyForwardingEquality.toBytes(LazyForwardingEquality.java:111)
        at com.diffplug.spotless.FormatterStepEqualityOnStateSerialization.lambda$serializedState$0(FormatterStepEqualityOnStateSerialization.java:93)
        at com.diffplug.spotless.ThrowingEx.get(ThrowingEx.java:67)
        at com.diffplug.spotless.FormatterStepEqualityOnStateSerialization.serializedState(FormatterStepEqualityOnStateSerialization.java:93)
        at com.diffplug.spotless.FormatterStepEqualityOnStateSerialization.hashCode(FormatterStepEqualityOnStateSerialization.java:73)
        at com.diffplug.spotless.FormatterStepSerializationRoundtrip$HackClone.hashCode(FormatterStepSerializationRoundtrip.java:137)
        at com.diffplug.spotless.ConfigurationCacheHackList.hashCode(ConfigurationCacheHackList.java:148)
        at org.gradle.internal.execution.impl.DefaultInputFingerprinter$InputCollectingVisitor.visitInputProperty(DefaultInputFingerprinter.java:114)
        at org.gradle.api.internal.tasks.execution.TaskExecution.visitRegularInputs(TaskExecution.java:315)
        at org.gradle.internal.execution.impl.DefaultInputFingerprinter.fingerprintInputProperties(DefaultInputFingerprinter.java:63)
        at org.gradle.internal.execution.steps.AbstractCaptureStateBeforeExecutionStep.captureExecutionStateWithOutputs(AbstractCaptureStateBeforeExecutionStep.java:109)
        at org.gradle.internal.execution.steps.AbstractCaptureStateBeforeExecutionStep.lambda$captureExecutionState$0(AbstractCaptureStateBeforeExecutionStep.java:74)
        at org.gradle.internal.execution.steps.BuildOperationStep$1.call(BuildOperationStep.java:37)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:209)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:204)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$2.execute(DefaultBuildOperationRunner.java:66)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$2.execute(DefaultBuildOperationRunner.java:59)
        at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:166)
        at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:59)
        at org.gradle.internal.operations.DefaultBuildOperationRunner.call(DefaultBuildOperationRunner.java:53)
        at org.gradle.internal.execution.steps.BuildOperationStep.operation(BuildOperationStep.java:34)
        at org.gradle.internal.execution.steps.AbstractCaptureStateBeforeExecutionStep.captureExecutionState(AbstractCaptureStateBeforeExecutionStep.java:69)
        at org.gradle.internal.execution.steps.AbstractCaptureStateBeforeExecutionStep.execute(AbstractCaptureStateBeforeExecutionStep.java:62)
        at org.gradle.internal.execution.steps.AbstractCaptureStateBeforeExecutionStep.execute(AbstractCaptureStateBeforeExecutionStep.java:43)
        at org.gradle.internal.execution.steps.AbstractSkipEmptyWorkStep.executeWithNonEmptySources(AbstractSkipEmptyWorkStep.java:125)
        at org.gradle.internal.execution.steps.AbstractSkipEmptyWorkStep.execute(AbstractSkipEmptyWorkStep.java:56)
        at org.gradle.internal.execution.steps.AbstractSkipEmptyWorkStep.execute(AbstractSkipEmptyWorkStep.java:36)
        at org.gradle.internal.execution.steps.legacy.MarkSnapshottingInputsStartedStep.execute(MarkSnapshottingInputsStartedStep.java:38)
        at org.gradle.internal.execution.steps.LoadPreviousExecutionStateStep.execute(LoadPreviousExecutionStateStep.java:36)
        at org.gradle.internal.execution.steps.LoadPreviousExecutionStateStep.execute(LoadPreviousExecutionStateStep.java:23)
        at org.gradle.internal.execution.steps.HandleStaleOutputsStep.execute(HandleStaleOutputsStep.java:75)
        at org.gradle.internal.execution.steps.HandleStaleOutputsStep.execute(HandleStaleOutputsStep.java:41)
        at org.gradle.internal.execution.steps.AssignMutableWorkspaceStep.lambda$execute$0(AssignMutableWorkspaceStep.java:35)
        at org.gradle.api.internal.tasks.execution.TaskExecution$4.withWorkspace(TaskExecution.java:289)
        at org.gradle.internal.execution.steps.AssignMutableWorkspaceStep.execute(AssignMutableWorkspaceStep.java:31)
        at org.gradle.internal.execution.steps.AssignMutableWorkspaceStep.execute(AssignMutableWorkspaceStep.java:22)
        at org.gradle.internal.execution.steps.ChoosePipelineStep.execute(ChoosePipelineStep.java:40)
        at org.gradle.internal.execution.steps.ChoosePipelineStep.execute(ChoosePipelineStep.java:23)
        at org.gradle.internal.execution.steps.ExecuteWorkBuildOperationFiringStep.lambda$execute$2(ExecuteWorkBuildOperationFiringStep.java:67)
        at org.gradle.internal.execution.steps.ExecuteWorkBuildOperationFiringStep.execute(ExecuteWorkBuildOperationFiringStep.java:67)
        at org.gradle.internal.execution.steps.ExecuteWorkBuildOperationFiringStep.execute(ExecuteWorkBuildOperationFiringStep.java:39)
        at org.gradle.internal.execution.steps.IdentityCacheStep.execute(IdentityCacheStep.java:46)
        at org.gradle.internal.execution.steps.IdentityCacheStep.execute(IdentityCacheStep.java:34)
        at org.gradle.internal.execution.steps.IdentifyStep.execute(IdentifyStep.java:48)
        at org.gradle.internal.execution.steps.IdentifyStep.execute(IdentifyStep.java:35)
        at org.gradle.internal.execution.impl.DefaultExecutionEngine$1.execute(DefaultExecutionEngine.java:61)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeIfValid(ExecuteActionsTaskExecuter.java:127)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.execute(ExecuteActionsTaskExecuter.java:116)
        at org.gradle.api.internal.tasks.execution.ProblemsTaskPathTrackingTaskExecuter.execute(ProblemsTaskPathTrackingTaskExecuter.java:40)
        at org.gradle.api.internal.tasks.execution.FinalizePropertiesTaskExecuter.execute(FinalizePropertiesTaskExecuter.java:46)
        at org.gradle.api.internal.tasks.execution.ResolveTaskExecutionModeExecuter.execute(ResolveTaskExecutionModeExecuter.java:51)
        at org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter.execute(SkipTaskWithNoActionsExecuter.java:57)
        at org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execute(SkipOnlyIfTaskExecuter.java:74)
        at org.gradle.api.internal.tasks.execution.CatchExceptionTaskExecuter.execute(CatchExceptionTaskExecuter.java:36)
        at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.executeTask(EventFiringTaskExecuter.java:77)
        at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.call(EventFiringTaskExecuter.java:55)
        at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.call(EventFiringTaskExecuter.java:52)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:209)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:204)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$2.execute(DefaultBuildOperationRunner.java:66)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$2.execute(DefaultBuildOperationRunner.java:59)
        at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:166)
        at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:59)
        at org.gradle.internal.operations.DefaultBuildOperationRunner.call(DefaultBuildOperationRunner.java:53)
        at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter.execute(EventFiringTaskExecuter.java:52)
        at org.gradle.execution.plan.LocalTaskNodeExecutor.execute(LocalTaskNodeExecutor.java:42)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$InvokeNodeExecutorsAction.execute(DefaultTaskExecutionGraph.java:331)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$InvokeNodeExecutorsAction.execute(DefaultTaskExecutionGraph.java:318)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.lambda$execute$0(DefaultTaskExecutionGraph.java:314)
        at org.gradle.internal.operations.CurrentBuildOperationRef.with(CurrentBuildOperationRef.java:85)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.execute(DefaultTaskExecutionGraph.java:314)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.execute(DefaultTaskExecutionGraph.java:303)
        at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.execute(DefaultPlanExecutor.java:459)
        at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.run(DefaultPlanExecutor.java:376)
        at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:64)
        at org.gradle.internal.concurrent.AbstractManagedExecutor$1.run(AbstractManagedExecutor.java:48)
Caused by: java.io.NotSerializableException: REDACTED
        at com.diffplug.spotless.FormatterStepSerializationRoundtrip.writeObject(FormatterStepSerializationRoundtrip.java:81)
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
        at com.diffplug.spotless.FormatterStepSerializationRoundtrip$HackClone.writeObject(FormatterStepSerializationRoundtrip.java:118)
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
        at com.diffplug.spotless.ConfigurationCacheHackList.writeObject(ConfigurationCacheHackList.java:76)
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
        at com.diffplug.spotless.LazyForwardingEquality.toBytes(LazyForwardingEquality.java:109)
        ... 75 more


BUILD FAILED in 1s
11 actionable tasks: 1 executed, 10 up-to-date

[nedtwigg]

So Groovy Closures take this codepath

https://github.com/diffplug/spotless/blob/8219f37abfc8817fcd30571552501c12b01558eb/plugin-gradle/src/main/java/com/diffplug/gradle/spotless/FormatExtension.java#L458-L461

And Kotlin takes this one

https://github.com/diffplug/spotless/blob/8219f37abfc8817fcd30571552501c12b01558eb/plugin-gradle/src/main/java/com/diffplug/gradle/spotless/FormatExtension.java#L484-L488

https://github.com/diffplug/spotless/blob/8219f37abfc8817fcd30571552501c12b01558eb/lib/src/main/java/com/diffplug/spotless/FormatterFunc.java#L27-L28

I suppose this workaround should work

java {
  custom("Refuse wildcard imports", object : Serializable, FormatterFunc {
    override fun apply(input: String) : String {
      if (input.contains("*;\n")) {
        throw GradleException("No wildcard imports allowed.")
      }
    }
  })
}

but it's not great... Gradle jumped through a bunch of hoops to make the Groovy Closure serialization work, I wonder if they have any tricks up their sleeve for Kotlin script...

[cmuchinsky]

Thanks @nedtwigg, your workaround (with a return input inserted after the if condition) works for me locally

[bric3]

We had this issue as well on Mockito. Thanks for the workaround. I wonder if making FormatterFunc implements java.io.Serializable would work.