Temporary workaround: rename scratch files with kt extension to kts before additional api will be added in IDEA

idea/idea-jvm/src/org/jetbrains/kotlin/idea/scratch/ScratchFileModuleInfoProvider.kt

@@ -19,6 +19,7 @@ package org.jetbrains.kotlin.idea.scratch
 import com.intellij.codeInsight.daemon.DaemonCodeAnalyzer
 import com.intellij.ide.scratch.ScratchFileService
 import com.intellij.openapi.components.AbstractProjectComponent
+import com.intellij.openapi.diagnostic.Logger
 import com.intellij.openapi.fileEditor.FileEditorManager
 import com.intellij.openapi.fileEditor.FileEditorManagerListener
 import com.intellij.openapi.module.Module
@@ -26,13 +27,18 @@ import com.intellij.openapi.project.Project
 import com.intellij.openapi.roots.ProjectRootManager
 import com.intellij.openapi.vfs.VirtualFile
 import com.intellij.psi.PsiManager
+import org.jetbrains.kotlin.idea.KotlinFileType
 import org.jetbrains.kotlin.idea.caches.resolve.NotUnderContentRootModuleInfo
 import org.jetbrains.kotlin.idea.caches.resolve.productionSourceInfo
 import org.jetbrains.kotlin.idea.caches.resolve.testSourceInfo
+import org.jetbrains.kotlin.idea.util.application.runWriteAction
+import org.jetbrains.kotlin.parsing.KotlinParserDefinition.Companion.STD_SCRIPT_EXT
+import org.jetbrains.kotlin.parsing.KotlinParserDefinition.Companion.STD_SCRIPT_SUFFIX
 import org.jetbrains.kotlin.psi.KtFile
 import org.jetbrains.kotlin.psi.moduleInfo
 
 class ScratchFileModuleInfoProvider(project: Project) : AbstractProjectComponent(project) {
+    private val LOG =Logger.getInstance(this.javaClass)
 
     override fun projectOpened() {
         myProject.messageBus.connect(myProject).subscribe(FileEditorManagerListener.FILE_EDITOR_MANAGER, ScratchFileModuleListener())
@@ -45,6 +51,24 @@ class ScratchFileModuleInfoProvider(project: Project) : AbstractProjectComponent
 
             val ktFile = PsiManager.getInstance(myProject).findFile(file) as? KtFile ?: return
 
+            // Hack before api in IDEA will be introduced
+            if (file.extension == KotlinFileType.EXTENSION) {
+                runWriteAction {
+                    var newName = file.nameWithoutExtension + STD_SCRIPT_EXT
+                    var i = 1
+                    while (file.parent.findChild(newName) != null) {
+                        newName = file.nameWithoutExtension + "_" + i + STD_SCRIPT_EXT
+                        i++
+                    }
+                    file.rename(this, newName)
+                }
+            }
+
+            if (file.extension != STD_SCRIPT_SUFFIX) {
+                LOG.error("Kotlin Scratch file should have .kts extension. Cannot add scratch panel for ${file.path}")
+                return
+            }
+
             getScratchPanel(ktFile)?.let { panel ->
                 ktFile.moduleInfo = getModuleInfo(panel.getModule())