Suggest named classes instead of anonymous nested ones (#2003)

* ClassNotFound exception for an anonymous class #1025
Select a single "outer" method in the dialog if caret stays inside anonymous class scope

Author: Vassiliy-Kudryashov

utbot-intellij/src/main/kotlin/org/utbot/intellij/plugin/language/JavaLanguage.kt

@@ -64,7 +64,7 @@ object JvmLanguageAssistant : LanguageAssistant() {
             val psiElementHandler = PsiElementHandler.makePsiElementHandler(file)
 
             if (psiElementHandler.isCreateTestActionAvailable(element)) {
-                val srcClass = psiElementHandler.containingClass(element) ?: return null
+                val srcClass = psiElementHandler.identifiedContainingClass(element) ?: return null
                 val srcSourceRoot = srcClass.getSourceRoot() ?: return null
                 val srcMembers = srcClass.extractFirstLevelMembers(false)
                 val focusedMethod = focusedMethodOrNull(element, srcMembers, psiElementHandler)
@@ -94,7 +94,7 @@ object JvmLanguageAssistant : LanguageAssistant() {
                 val psiElementHandler = PsiElementHandler.makePsiElementHandler(file)
 
                 if (psiElementHandler.isCreateTestActionAvailable(element)) {
-                    psiElementHandler.containingClass(element)?.let {
+                    psiElementHandler.identifiedContainingClass(element)?.let {
                         srcClasses += setOf(it)
                         extractMembersFromSrcClasses = true
                         val memberInfoList = runReadAction<List<MemberInfo>> {
@@ -148,6 +148,11 @@ object JvmLanguageAssistant : LanguageAssistant() {
         return null
     }
 
+    private fun PsiElementHandler.identifiedContainingClass(element: PsiElement): PsiClass? {
+        val clazz = containingClass(element)
+        return if (clazz is PsiAnonymousClass) PsiTreeUtil.getParentOfType(clazz, PsiClass::class.java) else clazz
+    }
+
     /**
      * Validates that a set of source classes matches some requirements from [isInvalid].
      * If no one of them matches, shows a warning about the first mismatch reason.
@@ -207,8 +212,13 @@ object JvmLanguageAssistant : LanguageAssistant() {
         // Thus, make transition to the Psi if it is required.
         val currentMethod = PsiTreeUtil.getParentOfType(element, psiElementHandler.methodClass)
             ?.let { psiElementHandler.toPsi(it, PsiMethod::class.java) }
+        // For anonymous class, we cannot select the nearest parent method directly.
+        // So, we have to suggest the nearest "outer" method from the named class.
+        val topmostCurrentMethod = PsiTreeUtil.getTopmostParentOfType(element, psiElementHandler.methodClass)
+            ?.let { psiElementHandler.toPsi(it, PsiMethod::class.java) }
 
         return methods.singleOrNull { it.member == currentMethod }
+            ?: methods.singleOrNull { it.member == topmostCurrentMethod }
     }
 
     private fun getAllClasses(directory: PsiDirectory): Set<PsiClass> {