[IntelliJ plugin] Platform error if configuration file is removed

[kajsa]

Expected Behavior

A missing config file should generate a warning, ideally with a link to the setting page to update the config file location.

Observed Behavior

IDE fatal error occurs, with this stacktrace:

ExternalToolPass:

com.intellij.diagnostic.PluginException: annotator: io.gitlab.arturbosch.detekt.DetektAnnotator@250bd26b (class io.gitlab.arturbosch.detekt.DetektAnnotator) [Plugin: detekt]
	at com.intellij.ide.plugins.PluginManagerCore.createPluginException(PluginManagerCore.java:403)
	at com.intellij.diagnostic.PluginProblemReporterImpl.createPluginExceptionByClass(PluginProblemReporterImpl.java:12)
	at com.intellij.diagnostic.PluginException.createByClass(PluginException.java:72)
	at com.intellij.codeInsight.daemon.impl.ExternalToolPass.process(ExternalToolPass.java:253)
	at com.intellij.codeInsight.daemon.impl.ExternalToolPass.doAnnotate(ExternalToolPass.java:206)
	at com.intellij.codeInsight.daemon.impl.ExternalToolPass.access$500(ExternalToolPass.java:39)
	at com.intellij.codeInsight.daemon.impl.ExternalToolPass$1.lambda$run$1(ExternalToolPass.java:179)
	at com.intellij.openapi.progress.util.BackgroundTaskUtil.lambda$runUnderDisposeAwareIndicator$11(BackgroundTaskUtil.java:244)
	at com.intellij.openapi.progress.impl.CoreProgressManager.lambda$runProcess$3(CoreProgressManager.java:185)
	at com.intellij.openapi.progress.impl.CoreProgressManager.lambda$runProcess$2(CoreProgressManager.java:169)
	at com.intellij.openapi.progress.impl.CoreProgressManager.registerIndicatorAndRun(CoreProgressManager.java:591)
	at com.intellij.openapi.progress.impl.CoreProgressManager.executeProcessUnderProgress(CoreProgressManager.java:537)
	at com.intellij.openapi.progress.impl.ProgressManagerImpl.executeProcessUnderProgress(ProgressManagerImpl.java:59)
	at com.intellij.openapi.progress.impl.CoreProgressManager.runProcess(CoreProgressManager.java:156)
	at com.intellij.openapi.progress.impl.CoreProgressManager.runProcess(CoreProgressManager.java:185)
	at com.intellij.openapi.progress.util.BackgroundTaskUtil.runUnderDisposeAwareIndicator(BackgroundTaskUtil.java:264)
	at com.intellij.openapi.progress.util.BackgroundTaskUtil.runUnderDisposeAwareIndicator(BackgroundTaskUtil.java:243)
	at com.intellij.codeInsight.daemon.impl.ExternalToolPass$1.run(ExternalToolPass.java:178)
	at com.intellij.util.ui.update.MergingUpdateQueue.execute(MergingUpdateQueue.java:324)
	at com.intellij.util.ui.update.MergingUpdateQueue.execute(MergingUpdateQueue.java:314)
	at com.intellij.util.ui.update.MergingUpdateQueue.lambda$flush$1(MergingUpdateQueue.java:264)
	at com.intellij.util.ui.update.MergingUpdateQueue.flush(MergingUpdateQueue.java:278)
	at com.intellij.util.ui.update.MergingUpdateQueue.run(MergingUpdateQueue.java:233)
	at com.intellij.util.concurrency.QueueProcessor.runSafely(QueueProcessor.java:231)
	at com.intellij.util.Alarm$Request.runSafely(Alarm.java:368)
	at com.intellij.util.Alarm$Request.run(Alarm.java:355)
	at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
	at com.intellij.util.concurrency.SchedulingWrapper$MyScheduledFutureTask.run(SchedulingWrapper.java:224)
	at com.intellij.util.concurrency.BoundedTaskExecutor.doRun(BoundedTaskExecutor.java:207)
	at com.intellij.util.concurrency.BoundedTaskExecutor.access$100(BoundedTaskExecutor.java:29)
	at com.intellij.util.concurrency.BoundedTaskExecutor$1.lambda$run$0(BoundedTaskExecutor.java:185)
	at com.intellij.util.ConcurrencyUtil.runUnderThreadName(ConcurrencyUtil.java:208)
	at com.intellij.util.concurrency.BoundedTaskExecutor$1.run(BoundedTaskExecutor.java:181)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
	at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: com.beust.jcommander.ParameterException: Provided path '/Users/kanderson/git/cweos/detekt/default-detekt-config.yml' does not exist!
	at io.gitlab.arturbosch.detekt.cli.ExistingPathConverter.convert(PathConverters.kt:17)
	at io.gitlab.arturbosch.detekt.cli.ExistingPathConverter.convert(PathConverters.kt:13)
	at io.gitlab.arturbosch.detekt.cli.DetektInputPathConverter$convert$2.invoke(PathConverters.kt:34)
	at io.gitlab.arturbosch.detekt.cli.DetektInputPathConverter$convert$2.invoke(PathConverters.kt:29)
	at kotlin.sequences.TransformingSequence$iterator$1.next(Sequences.kt:172)
	at kotlin.sequences.SequencesKt___SequencesKt.toCollection(_Sequences.kt:702)
	at kotlin.sequences.SequencesKt___SequencesKt.toMutableList(_Sequences.kt:732)
	at kotlin.sequences.SequencesKt___SequencesKt.toList(_Sequences.kt:723)
	at io.gitlab.arturbosch.detekt.cli.DetektInputPathConverter$DefaultImpls.convert(PathConverters.kt:35)
	at io.gitlab.arturbosch.detekt.cli.MultipleExistingPathConverter.convert(PathConverters.kt:44)
	at io.gitlab.arturbosch.detekt.cli.ConfigurationsKt.parsePathConfig(Configurations.kt:54)
	at io.gitlab.arturbosch.detekt.cli.ConfigurationsKt.loadConfiguration(Configurations.kt:22)
	at io.gitlab.arturbosch.detekt.DetektAnnotator.processingSettings(DetektAnnotator.kt:89)
	at io.gitlab.arturbosch.detekt.DetektAnnotator.runDetekt(DetektAnnotator.kt:55)
	at io.gitlab.arturbosch.detekt.DetektAnnotator.doAnnotate(DetektAnnotator.kt:45)
	at io.gitlab.arturbosch.detekt.DetektAnnotator.doAnnotate(DetektAnnotator.kt:28)
	at com.intellij.codeInsight.daemon.impl.ExternalToolPass.doAnnotate(ExternalToolPass.java:203)
	... 32 more

Steps to Reproduce

1. install detekt IntelliJ plugin
2. Under Project Settings -> Tools -> detekt, point to a valid detekt configuration file
3. Move the configuration file elsewhere in the filesystem
4. IDE Fatal Error occurs

Context

In the course of setting up a project at a new employer, I had cloned the project to 2 different locations. Once I got the project set up properly, I removed the "bad" clone, but I had accidentally pointed to that location when configuring the detekt plugin. A missing configuration file shouldn't result in an IDE level fatal error, it should be handled more gracefully, ideally by directing the idiot user (me, in this case) where in Project Settings to change the configuration file location.

Your Environment

• Version of detekt used: 1.0.0RC12
• Version of detekt IntelliJ plugin: 0.3.1
• Version of Gradle used (if applicable): 5.6
• Version of IntelliJ used: 2019.2.1
• Operating System and version: macOS 10.14.6
• Link to your project (if it's a public repository):

[schalkms]

Very much related to #22

[arturbosch]

Should be fixed by #45