Show notification if provided config is invalid

Author: bagage

Diff for: src/main/kotlin/io/gitlab/arturbosch/detekt/DetektAnnotator.kt

@@ -2,8 +2,15 @@ package io.gitlab.arturbosch.detekt
 
 import com.intellij.lang.annotation.AnnotationHolder
 import com.intellij.lang.annotation.ExternalAnnotator
+import com.intellij.notification.Notification
+import com.intellij.notification.NotificationType
+import com.intellij.openapi.actionSystem.AnAction
+import com.intellij.openapi.actionSystem.AnActionEvent
+import com.intellij.openapi.application.ApplicationManager
 import com.intellij.openapi.command.WriteCommandAction
 import com.intellij.openapi.fileEditor.FileDocumentManager
+import com.intellij.openapi.options.newEditor.SettingsDialog
+import com.intellij.openapi.project.Project
 import com.intellij.openapi.util.Computable
 import com.intellij.openapi.util.TextRange
 import com.intellij.openapi.vfs.VirtualFile
@@ -12,12 +19,14 @@ import io.gitlab.arturbosch.detekt.api.Finding
 import io.gitlab.arturbosch.detekt.api.TextLocation
 import io.gitlab.arturbosch.detekt.cli.CliArgs
 import io.gitlab.arturbosch.detekt.cli.loadConfiguration
+import io.gitlab.arturbosch.detekt.config.DetektConfig
 import io.gitlab.arturbosch.detekt.config.DetektConfigStorage
 import io.gitlab.arturbosch.detekt.config.NoAutoCorrectConfig
 import io.gitlab.arturbosch.detekt.core.DetektFacade
 import io.gitlab.arturbosch.detekt.core.FileProcessorLocator
 import io.gitlab.arturbosch.detekt.core.ProcessingSettings
 import io.gitlab.arturbosch.detekt.core.RuleSetLocator
+import java.io.File
 import java.nio.file.Paths
 import java.util.concurrent.ForkJoinPool
 
@@ -52,9 +61,12 @@ class DetektAnnotator : ExternalAnnotator<PsiFile, List<Finding>>() {
         configuration: DetektConfigStorage
     ): List<Finding> {
         val virtualFile = collectedInfo.originalFile.virtualFile
-        val settings = processingSettings(virtualFile, configuration)
-        val result = createFacade(settings, configuration).run()
-        return result.findings.flatMap { it.value }
+        val settings = processingSettings(collectedInfo.project, virtualFile, configuration)
+
+        return settings?.let {
+            val result = createFacade(settings, configuration).run()
+            result.findings.flatMap { it.value }
+        } ?: emptyList()
     }
 
     override fun apply(
@@ -76,19 +88,43 @@ class DetektAnnotator : ExternalAnnotator<PsiFile, List<Finding>>() {
 
     private fun TextLocation.toTextRange(): TextRange = TextRange.create(start, end)
 
-    private fun processingSettings(virtualFile: VirtualFile,
-                                   configStorage: DetektConfigStorage) =
-        ProcessingSettings(
+    private fun processingSettings(
+        project: Project,
+        virtualFile: VirtualFile,
+        configStorage: DetektConfigStorage
+    ): ProcessingSettings? {
+        if (configStorage.rulesPath.isNotEmpty()) {
+            val path = File(configStorage.rulesPath)
+            if (!path.exists()) {
+                val n = Notification(
+                    "Detekt",
+                    "Configuration file not found",
+                    "The provided detekt configuration file <b>${path.absolutePath}</b> does not exist. Skipping detekt run.",
+                    NotificationType.WARNING
+                )
+                n.addAction(object : AnAction("Open Detekt projects settings") {
+                    override fun actionPerformed(e: AnActionEvent) {
+                        val dialog = SettingsDialog(project, "Detekt project settings", DetektConfig(project), true, true)
+                        ApplicationManager.getApplication().invokeLater(dialog::show);
+                    }
+                })
+                n.notify(project)
+                return null
+            }
+        }
+
+
+
+        return ProcessingSettings(
             inputPath = Paths.get(virtualFile.path),
             config = NoAutoCorrectConfig(CliArgs().apply {
-                if (configStorage.rulesPath.isNotEmpty()) {
-                    config = configStorage.rulesPath
-                    failFast = configStorage.failFast
-                    buildUponDefaultConfig = configStorage.buildUponDefaultConfig
-                }
+                config = configStorage.rulesPath
+                failFast = configStorage.failFast
+                buildUponDefaultConfig = configStorage.buildUponDefaultConfig
             }.loadConfiguration()),
             executorService = ForkJoinPool.commonPool()
         )
+    }
 
     private fun createFacade(settings: ProcessingSettings, configuration: DetektConfigStorage): DetektFacade {
         var providers = RuleSetLocator(settings).load()