The demo silently depends on NPM due to Spotless

[oleg-nenashev]

FYI @sivaprasadreddy , caught it in my experiments in the dev container:

Step 'prettier-format' found problem in 'src/main/java/com/testcontainers/demo/Message.java':
Can't automatically determine npm executable and none was specifically supplied!

Spotless tries to find your npm executable automatically. It looks for npm in the following places:
- An executable referenced by the java system property 'npm.exec' - if such a system property exists.
- The environment variable 'NVM_BIN' - if such an environment variable exists.
- The environment variable 'NVM_SYMLINK' - if such an environment variable exists.
- The environment variable 'NODE_PATH' - if such an environment variable exists.
- In your 'PATH' environment variable

If autodiscovery fails for your system, try to set one of the environment variables correctly or
try setting the system property 'npm.exec' in the build process to override autodiscovery.
java.lang.IllegalStateException: Can't automatically determine npm executable and none was specifically supplied!

Spotless tries to find your npm executable automatically. It looks for npm in the following places:
- An executable referenced by the java system property 'npm.exec' - if such a system property exists.
- The environment variable 'NVM_BIN' - if such an environment variable exists.
- The environment variable 'NVM_SYMLINK' - if such an environment variable exists.
- The environment variable 'NODE_PATH' - if such an environment variable exists.
- In your 'PATH' environment variable

If autodiscovery fails for your system, try to set one of the environment variables correctly or
try setting the system property 'npm.exec' in the build process to override autodiscovery.
        at com.diffplug.spotless.npm.NpmPathResolver.lambda$resolveNpmExecutable$0(NpmPathResolver.java:60)
        at java.base/java.util.Optional.orElseThrow(Optional.java:403)
        at com.diffplug.spotless.npm.NpmPathResolver.resolveNpmExecutable(NpmPathResolver.java:60)
        at com.diffplug.spotless.npm.NpmPathResolver.resolveNodeExecutable(NpmPathResolver.java:75)
        at com.diffplug.spotless.npm.NpmFormatterStepLocations.nodeExecutable(NpmFormatterStepLocations.java:71)
        at com.diffplug.spotless.npm.StandardNpmProcessFactory$AbstractStandardNpmProcess.environmentVariables(StandardNpmProcessFactory.java:63)
        at com.diffplug.spotless.npm.StandardNpmProcessFactory$AbstractStandardNpmProcess.doStart(StandardNpmProcessFactory.java:68)
        at com.diffplug.spotless.npm.StandardNpmProcessFactory$NpmInstall.waitFor(StandardNpmProcessFactory.java:107)
        at com.diffplug.spotless.npm.NodeApp.optimizedNpmInstall(NodeApp.java:96)
        at com.diffplug.spotless.ThrowingEx.run(ThrowingEx.java:55)
        at com.diffplug.spotless.npm.TimedLogger$TimedExec.run(TimedLogger.java:195)
        at com.diffplug.spotless.npm.NodeApp.npmInstall(NodeApp.java:91)
        at com.diffplug.spotless.npm.NpmFormatterStepStateBase.prepareNodeServer(NpmFormatterStepStateBase.java:72)
        at com.diffplug.spotless.npm.NpmFormatterStepStateBase.assertNodeServerDirReady(NpmFormatterStepStateBase.java:82)
        at com.diffplug.spotless.npm.NpmFormatterStepStateBase.npmRunServer(NpmFormatterStepStateBase.java:95)
        at com.diffplug.spotless.npm.PrettierFormatterStep$State.createFormatterFunc(PrettierFormatterStep.java:92)
        at com.diffplug.spotless.FormatterStepImpl$Standard.format(FormatterStepImpl.java:80)
        at com.diffplug.spotless.FormatterStep$Strict.format(FormatterStep.java:103)
        at com.diffplug.spotless.Formatter.compute(Formatter.java:246)
        at com.diffplug.spotless.PaddedCell.calculateDirtyState(PaddedCell.java:203)
        at com.diffplug.spotless.PaddedCell.calculateDirtyState(PaddedCell.java:190)
        at com.diffplug.gradle.spotless.SpotlessTaskImpl.processInputFile(SpotlessTaskImpl.java:105)
        at com.diffplug.gradle.spotless.SpotlessTaskImpl.performAction(SpotlessTaskImpl.java:89)
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
        at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.base/java.lang.reflect.Method.invoke(Method.java:568)
        at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:125)
        at org.gradle.api.internal.project.taskfactory.IncrementalTaskAction.doExecute(IncrementalTaskAction.java:45)
        at org.gradle.api.internal.project.taskfactory.StandardTaskAction.execute(StandardTaskAction.java:51)
        at org.gradle.api.internal.project.taskfactory.IncrementalTaskAction.execute(IncrementalTaskAction.java:26)
        at org.gradle.api.internal.project.taskfactory.StandardTaskAction.execute(StandardTaskAction.java:29)
        at org.gradle.api.internal.tasks.execution.TaskExecution$3.run(TaskExecution.java:244)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$1.execute(DefaultBuildOperationRunner.java:29)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$1.execute(DefaultBuildOperationRunner.java:26)
        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:157)
        at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:59)
        at org.gradle.internal.operations.DefaultBuildOperationRunner.run(DefaultBuildOperationRunner.java:47)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:68)
        at org.gradle.api.internal.tasks.execution.TaskExecution.executeAction(TaskExecution.java:229)
        at org.gradle.api.internal.tasks.execution.TaskExecution.executeActions(TaskExecution.java:212)
        at org.gradle.api.internal.tasks.execution.TaskExecution.executeWithPreviousOutputFiles(TaskExecution.java:195)
        at org.gradle.api.internal.tasks.execution.TaskExecution.execute(TaskExecution.java:162)
        at org.gradle.internal.execution.steps.ExecuteStep.executeInternal(ExecuteStep.java:105)
        at org.gradle.internal.execution.steps.ExecuteStep.access$000(ExecuteStep.java:44)
        at org.gradle.internal.execution.steps.ExecuteStep$1.call(ExecuteStep.java:59)
        at org.gradle.internal.execution.steps.ExecuteStep$1.call(ExecuteStep.java:56)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:200)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:195)
        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:157)
        at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:59)
        at org.gradle.internal.operations.DefaultBuildOperationRunner.call(DefaultBuildOperationRunner.java:53)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor.call(DefaultBuildOperationExecutor.java:73)
        at org.gradle.internal.execution.steps.ExecuteStep.execute(ExecuteStep.java:56)
        at org.gradle.internal.execution.steps.ExecuteStep.execute(ExecuteStep.java:44)
        at org.gradle.internal.execution.steps.CancelExecutionStep.execute(CancelExecutionStep.java:41)
        at org.gradle.internal.execution.steps.TimeoutStep.executeWithoutTimeout(TimeoutStep.java:74)
        at org.gradle.internal.execution.steps.TimeoutStep.execute(TimeoutStep.java:55)
        at org.gradle.internal.execution.steps.PreCreateOutputParentsStep.execute(PreCreateOutputParentsStep.java:50)
        at org.gradle.internal.execution.steps.PreCreateOutputParentsStep.execute(PreCreateOutputParentsStep.java:28)
        at org.gradle.internal.execution.steps.RemovePreviousOutputsStep.execute(RemovePreviousOutputsStep.java:67)
        at org.gradle.internal.execution.steps.RemovePreviousOutputsStep.execute(RemovePreviousOutputsStep.java:37)
        at org.gradle.internal.execution.steps.BroadcastChangingOutputsStep.execute(BroadcastChangingOutputsStep.java:61)
        at org.gradle.internal.execution.steps.BroadcastChangingOutputsStep.execute(BroadcastChangingOutputsStep.java:26)
        at org.gradle.internal.execution.steps.CaptureOutputsAfterExecutionStep.execute(CaptureOutputsAfterExecutionStep.java:67)
        at org.gradle.internal.execution.steps.CaptureOutputsAfterExecutionStep.execute(CaptureOutputsAfterExecutionStep.java:45)
        at org.gradle.internal.execution.steps.ResolveInputChangesStep.execute(ResolveInputChangesStep.java:40)
        at org.gradle.internal.execution.steps.ResolveInputChangesStep.execute(ResolveInputChangesStep.java:29)
        at org.gradle.internal.execution.steps.BuildCacheStep.executeWithoutCache(BuildCacheStep.java:189)
        at org.gradle.internal.execution.steps.BuildCacheStep.executeAndStoreInCache(BuildCacheStep.java:145)
        at org.gradle.internal.execution.steps.BuildCacheStep.lambda$executeWithCache$4(BuildCacheStep.java:101)
        at java.base/java.util.Optional.orElseGet(Optional.java:364)
        at org.gradle.internal.execution.steps.BuildCacheStep.lambda$executeWithCache$5(BuildCacheStep.java:101)
        at org.gradle.internal.Try$Success.map(Try.java:164)
        at org.gradle.internal.execution.steps.BuildCacheStep.executeWithCache(BuildCacheStep.java:85)
        at org.gradle.internal.execution.steps.BuildCacheStep.lambda$execute$0(BuildCacheStep.java:74)
        at org.gradle.internal.Either$Left.fold(Either.java:115)
        at org.gradle.internal.execution.caching.CachingState.fold(CachingState.java:62)
        at org.gradle.internal.execution.steps.BuildCacheStep.execute(BuildCacheStep.java:73)
        at org.gradle.internal.execution.steps.BuildCacheStep.execute(BuildCacheStep.java:48)
        at org.gradle.internal.execution.steps.StoreExecutionStateStep.execute(StoreExecutionStateStep.java:46)
        at org.gradle.internal.execution.steps.StoreExecutionStateStep.execute(StoreExecutionStateStep.java:35)
        at org.gradle.internal.execution.steps.SkipUpToDateStep.executeBecause(SkipUpToDateStep.java:76)
        at org.gradle.internal.execution.steps.SkipUpToDateStep.lambda$execute$2(SkipUpToDateStep.java:54)
        at java.base/java.util.Optional.orElseGet(Optional.java:364)
        at org.gradle.internal.execution.steps.SkipUpToDateStep.execute(SkipUpToDateStep.java:54)
        at org.gradle.internal.execution.steps.SkipUpToDateStep.execute(SkipUpToDateStep.java:36)
        at org.gradle.internal.execution.steps.legacy.MarkSnapshottingInputsFinishedStep.execute(MarkSnapshottingInputsFinishedStep.java:37)
        at org.gradle.internal.execution.steps.legacy.MarkSnapshottingInputsFinishedStep.execute(MarkSnapshottingInputsFinishedStep.java:27)
        at org.gradle.internal.execution.steps.ResolveIncrementalCachingStateStep.executeDelegate(ResolveIncrementalCachingStateStep.java:49)
        at org.gradle.internal.execution.steps.ResolveIncrementalCachingStateStep.executeDelegate(ResolveIncrementalCachingStateStep.java:27)
        at org.gradle.internal.execution.steps.AbstractResolveCachingStateStep.execute(AbstractResolveCachingStateStep.java:71)
        at org.gradle.internal.execution.steps.AbstractResolveCachingStateStep.execute(AbstractResolveCachingStateStep.java:39)
        at org.gradle.internal.execution.steps.ResolveChangesStep.execute(ResolveChangesStep.java:65)
        at org.gradle.internal.execution.steps.ResolveChangesStep.execute(ResolveChangesStep.java:36)
        at org.gradle.internal.execution.steps.ValidateStep.execute(ValidateStep.java:106)
        at org.gradle.internal.execution.steps.ValidateStep.execute(ValidateStep.java:55)
        at org.gradle.internal.execution.steps.AbstractCaptureStateBeforeExecutionStep.execute(AbstractCaptureStateBeforeExecutionStep.java:64)
        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 java.base/java.util.Optional.orElseGet(Optional.java:364)
        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.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:200)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:195)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$2.execute(DefaultBuildOperationRunner.java:66)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$2.execute(DefaultBuildOperationRunner.java:59)
        at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:157)
        at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:59)
        at org.gradle.internal.operations.DefaultBuildOperationRunner.call(DefaultBuildOperationRunner.java:53)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor.call(DefaultBuildOperationExecutor.java:73)
        at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter.execute(EventFiringTaskExecuter.java:52)
        at org.gradle.execution.plan.LocalTaskNodeExecutor.execute(LocalTaskNodeExecutor.java:42)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$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$0(DefaultTaskExecutionGraph.java:314)
        at org.gradle.internal.operations.CurrentBuildOperationRef.with(CurrentBuildOperationRef.java:80)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$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:463)
        at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.run(DefaultPlanExecutor.java:380)
        at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:64)
        at org.gradle.internal.concurrent.AbstractManagedExecutor$1.run(AbstractManagedExecutor.java:47)
        at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
        at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
        at java.base/java.lang.Thread.run(Thread.java:840)

[kiview]

This is correct. Do you propose we mention NPM in the README as a requirement, or removing the dependency?