New J2K: Promete class to object when init declaration present

nj2k/src/org/jetbrains/kotlin/nj2k/conversions/ClassToObjectPromotionConversion.kt

@@ -6,22 +6,28 @@
 package org.jetbrains.kotlin.nj2k.conversions
 
 import org.jetbrains.kotlin.nj2k.ConversionContext
+import org.jetbrains.kotlin.nj2k.getCompanion
 import org.jetbrains.kotlin.nj2k.tree.*
-import org.jetbrains.kotlin.nj2k.tree.impl.*
+import org.jetbrains.kotlin.nj2k.tree.impl.JKAnnotationListImpl
-import org.jetbrains.kotlin.utils.addToStdlib.firstIsInstanceOrNull
+import org.jetbrains.kotlin.nj2k.tree.impl.JKClassImpl
+import org.jetbrains.kotlin.nj2k.tree.impl.psi
 
 class ClassToObjectPromotionConversion(private val context: ConversionContext) : RecursiveApplicableConversionBase() {
     override fun applyToElement(element: JKTreeElement): JKTreeElement {
         if (element is JKClass && element.classKind == JKClass.ClassKind.CLASS) {
-            val companion =
+            val companion = element.getCompanion() ?: return recurse(element)
-                element.declarationList.firstIsInstanceOrNull<JKClass>()
-                    ?.takeIf { it.classKind == JKClass.ClassKind.COMPANION }
-                    ?: return recurse(element)
 
             val allDeclarationsMatches = element.declarationList.all {
                 when (it) {
                     is JKKtPrimaryConstructor -> it.parameters.isEmpty() && it.block.statements.isEmpty()
-                    is JKClass -> it.classKind == JKClass.ClassKind.COMPANION
+                    is JKKtInitDeclaration ->
+                        it.block.statements.all { statement ->
+                            when (statement) {
+                                is JKDeclarationStatement -> statement.declaredStatements.isEmpty()
+                                else -> false
+                            }
+                        }
+                    is JKClass -> true
                     else -> false
                 }
             }
@@ -35,8 +41,12 @@ class ClassToObjectPromotionConversion(private val context: ConversionContext) :
                         element.inheritance,
                         JKClass.ClassKind.OBJECT,
                         element.typeParameterList,
-                        companion.classBody.also {
+                        companion.classBody.also { body ->
-                            it.handleDeclarationsModifiers()
+                            body.handleDeclarationsModifiers()
+                            body.declarations += element.classBody.declarations.filter {
+                                //TODO preseve order
+                                it is JKClass && it.classKind != JKClass.ClassKind.COMPANION
+                            }.map { it.detached(element.classBody) }
                         },
                         JKAnnotationListImpl(),
                         element.extraModifiers,

nj2k/src/org/jetbrains/kotlin/nj2k/conversions/InnerClassConversion.kt

@@ -5,7 +5,10 @@
 
 package org.jetbrains.kotlin.nj2k.conversions
 
-import org.jetbrains.kotlin.nj2k.tree.*
+import org.jetbrains.kotlin.nj2k.tree.ExtraModifier
+import org.jetbrains.kotlin.nj2k.tree.JKClass
+import org.jetbrains.kotlin.nj2k.tree.JKTreeElement
+import org.jetbrains.kotlin.nj2k.tree.isLocalClass
 
 class InnerClassConversion : RecursiveApplicableConversionBase() {
     override fun applyToElement(element: JKTreeElement): JKTreeElement {
@@ -19,6 +22,7 @@ class InnerClassConversion : RecursiveApplicableConversionBase() {
 
     private fun applyArmed(element: JKTreeElement, outer: JKClass): JKTreeElement {
         if (element !is JKClass) return recurseArmed(element, outer)
+        if (element.classKind == JKClass.ClassKind.COMPANION) return recurseArmed(element, outer)
         if (element.isLocalClass()) return recurseArmed(element, outer)
 
         val static = element.extraModifiers.find { it == ExtraModifier.STATIC }

nj2k/src/org/jetbrains/kotlin/nj2k/expressions.kt

@@ -482,8 +482,24 @@ fun equalsExpression(left: JKExpression, right: JKExpression, symbolProvider: JK
         symbolProvider
     )
 
+fun createCompanion(declarations: List<JKDeclaration>): JKClass =
+    JKClassImpl(
+        JKNameIdentifierImpl(""),
+        JKInheritanceInfoImpl(emptyList(), emptyList()),
+        JKClass.ClassKind.COMPANION,
+        JKTypeParameterListImpl(),
+        JKClassBodyImpl(declarations),
+        JKAnnotationListImpl(),
+        emptyList(),
+        Visibility.PUBLIC,
+        Modality.FINAL
+    )
+
+fun JKClass.getCompanion(): JKClass? =
+    declarationList.firstOrNull { it is JKClass && it.classKind == JKClass.ClassKind.COMPANION } as? JKClass
+
 fun JKClass.getOrCreateCompainonObject(): JKClass =
-    (declarationList.firstOrNull { it is JKClass && it.classKind == JKClass.ClassKind.COMPANION } as? JKClass)
+    getCompanion()
         ?: JKClassImpl(
             JKNameIdentifierImpl(""),
             JKInheritanceInfoImpl(emptyList(), emptyList()),