[kotlin] KTIJ-36032 Show Kotlin not configured notification in source roots not registered as source roots

Merge-request: IJ-MR-183600
Merged-by: Victoria Petrakovich <Victoria.Petrakovich@jetbrains.com>

GitOrigin-RevId: 8ff45c5876fefaa6607759dd8791296ac85dd95d

plugins/kotlin/idea/tests/test/org/jetbrains/kotlin/idea/configuration/KotlinSetupEnvironmentNotificationProviderTest.kt

@@ -0,0 +1,37 @@
+// Copyright 2000-2025 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+package org.jetbrains.kotlin.idea.configuration
+
+import com.intellij.openapi.fileEditor.FileEditorManager
+import com.intellij.testFramework.fixtures.LightJavaCodeInsightFixtureTestCase
+import org.junit.Test
+import org.junit.internal.runners.JUnit38ClassRunner
+import org.junit.runner.RunWith
+
+@RunWith(JUnit38ClassRunner::class)
+class KotlinSetupEnvironmentNotificationProviderTest : LightJavaCodeInsightFixtureTestCase() {
+
+    @Test
+    fun testSrcMainKotlin() {
+        val kotlinFileRelativePath = "/src/main/kotlin/TestKotlin.kt"
+        createKotlinFile(kotlinFileRelativePath)
+        assertFileIsUnderSourceRoots(kotlinFileRelativePath, fileShouldBeUnderSourceRoots = true)
+    }
+
+    @Test
+    fun testSrcMainKotlin_smth() {
+        val kotlinFileRelativePath = "/src/main/kotlin_smth.kt"
+        createKotlinFile(kotlinFileRelativePath)
+        assertFileIsUnderSourceRoots(kotlinFileRelativePath, fileShouldBeUnderSourceRoots = false)
+    }
+
+    private fun createKotlinFile(kotlinFileRelativePath: String) {
+        val kotlinFile = myFixture.addFileToProject(kotlinFileRelativePath, "")
+        myFixture.openFileInEditor(kotlinFile.virtualFile)
+    }
+
+    private fun assertFileIsUnderSourceRoots(kotlinFileRelativePath: String, fileShouldBeUnderSourceRoots: Boolean) {
+        val selectedEditor = FileEditorManager.getInstance(project).selectedEditor
+        val selectedFile = selectedEditor?.file ?: error("file $kotlinFileRelativePath has to be in the editor")
+        assertEquals(fileShouldBeUnderSourceRoots, KotlinSetupEnvironmentNotificationProvider().fileIsUnderKotlinSourceRoot(selectedFile))
+    }
+}

plugins/kotlin/project-configuration/src/org/jetbrains/kotlin/idea/configuration/KotlinSetupEnvironmentNotificationProvider.kt

@@ -76,7 +76,7 @@ class KotlinSetupEnvironmentNotificationProvider : EditorNotificationProvider {
             return null
         }
 
-        if (!ModuleRootManager.getInstance(module).fileIndex.isInSourceContent(file)) {
+        if (!ModuleRootManager.getInstance(module).fileIndex.isInSourceContent(file) && !fileIsUnderKotlinSourceRoot(file)) {
             return null
         }
 
@@ -98,6 +98,10 @@ class KotlinSetupEnvironmentNotificationProvider : EditorNotificationProvider {
         return null
     }
 
+    fun fileIsUnderKotlinSourceRoot(file: VirtualFile): Boolean {
+        return file.path.contains("src/main/kotlin/") || file.path.contains("src/test/kotlin/")
+    }
+
     // We do this check only for JPS projects because for other build systems this problem is not topical
     private fun kotlinStdlibExistsOnDiskForJPS(module: Module, project: Project): Boolean {
         val moduleDependencies = module.findModuleEntity()?.dependencies ?: return false