Show line markers for JUnit test methods in abstract class

#KT-27977 Fixed

idea/idea-jvm/src/org/jetbrains/kotlin/idea/platform/JvmIdePlatformKindTooling.kt

@@ -68,7 +68,7 @@ class JvmIdePlatformKindTooling : IdePlatformKindTooling() {
                 val lightMethod = declaration.toLightMethods().firstOrNull() ?: return null
                 val lightClass = lightMethod.containingClass as? KtLightClass ?: return null
                 val framework = TestFrameworks.detectFramework(lightClass) ?: return null
-                if (!framework.isTestMethod(lightMethod)) return null
+                if (!framework.isTestMethod(lightMethod, /*checkAbstract = */ false)) return null
 
                 "java:test://${lightClass.qualifiedName}.${lightMethod.name}" to framework
             }

idea/testData/codeInsight/lineMarker/runMarkers/jUnitTestClassWithSubclasses.kt

@@ -5,12 +5,14 @@ import junit.framework.TestCase
 import org.junit.Test
 
 abstract class <lineMarker descr="*"><lineMarker descr="Run Test">KBase</lineMarker></lineMarker> : TestCase() {
+    // NOTE: this differs from Java tooling behaviour, see KT-27977
     @Test
-    fun testFoo() {
+    fun <lineMarker descr="Run Test">testFoo</lineMarker>() {
 
     }
 }
 
+
 class <lineMarker descr="*">KTest</lineMarker> : KBase() {
     @Test
     fun <lineMarker descr="*">testBar</lineMarker>() {
@@ -23,4 +25,13 @@ class <lineMarker descr="*">KTest2</lineMarker> : KBase() {
     fun <lineMarker descr="*">testBaz</lineMarker>() {
 
     }
-}
+}
+
+abstract class <lineMarker descr="*"><lineMarker descr="Run Test">AbstractClassWithoutInheritors</lineMarker></lineMarker> : TestCase() {
+    // NOTE: showing line markers for abstract method, which has no inheritors is not ideal, because those methods cannot actually be run
+    // Sadly, run configurations can actually be created for them (same in Java), so this behaviour is consistent with context menu
+    @Test
+    fun <lineMarker descr="Run Test">testFoo</lineMarker>() {
+
+    }
+}