New J2K: Add InterfaceWithFieldConversion

j2k/newSrc/org/jetbrains/kotlin/j2k/ConversionsRunner.kt

@@ -72,6 +72,7 @@ object ConversionsRunner {
             //Kotlin --> Kotlin conversions
             +InnerClassConversion()
             +StaticsToCompanionExtractConversion()
+            +InterfaceWithFieldConversion()
             +ClassToObjectPromotionConversion(context)
             +ImportStatementConversion()
             +SortClassMembersConversion()

j2k/newSrc/org/jetbrains/kotlin/j2k/conversions/InterfaceWithFieldConversion.kt

@@ -0,0 +1,26 @@
+/*
+ * Copyright 2010-2019 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.j2k.conversions
+
+import org.jetbrains.kotlin.j2k.*
+import org.jetbrains.kotlin.j2k.tree.*
+
+
+class InterfaceWithFieldConversion : RecursiveApplicableConversionBase() {
+    override fun applyToElement(element: JKTreeElement): JKTreeElement {
+        if (element !is JKClass) return recurse(element)
+        if (element.classKind != JKClass.ClassKind.INTERFACE) return recurse(element)
+        val finalFields = element.declarationList
+            .filterIsInstance<JKField>()
+            .filter { it.modality == Modality.FINAL }
+        if (finalFields.isNotEmpty()) {
+            element.classBody.declarations -= finalFields
+            val companion = element.getOrCreateCompainonObject()
+            companion.classBody.declarations += finalFields
+        }
+        return recurse(element)
+    }
+}

j2k/newSrc/org/jetbrains/kotlin/j2k/conversions/StaticsToCompanionExtractConversion.kt

@@ -5,6 +5,7 @@
 
 package org.jetbrains.kotlin.j2k.conversions
 
+import org.jetbrains.kotlin.j2k.getOrCreateCompainonObject
 import org.jetbrains.kotlin.j2k.tree.*
 import org.jetbrains.kotlin.j2k.tree.impl.*
 
@@ -16,38 +17,14 @@ class StaticsToCompanionExtractConversion : RecursiveApplicableConversionBase()
             declaration is JKExtraModifiersOwner &&
                     declaration.extraModifiers.any { it == ExtraModifier.STATIC }
         }
-
         if (statics.isEmpty()) return recurse(element)
-        val companion = findOrCreateCompanion(element)
-
+        val companion = element.getOrCreateCompainonObject()
 
         element.classBody.declarations -= statics
         companion.classBody.declarations += statics.onEach { declaration ->
             (declaration as JKExtraModifiersOwner)
             declaration.extraModifiers -= ExtraModifier.STATIC
         }
-
         return recurse(element)
     }
-
-    fun findOrCreateCompanion(element: JKClass): JKClass {
-        val companion = element.declarationList
-            .asSequence()
-            .filterIsInstance<JKClass>()
-            .firstOrNull { it.classKind == JKClass.ClassKind.COMPANION }
-
-        if (companion != null) return companion
-
-        return JKClassImpl(
-            JKNameIdentifierImpl(""),
-            JKInheritanceInfoImpl(emptyList(), emptyList()),
-            JKClass.ClassKind.COMPANION,
-            JKTypeParameterListImpl(),
-            JKClassBodyImpl(),
-            JKAnnotationListImpl(),
-            emptyList(),
-            Visibility.PUBLIC,
-            Modality.FINAL
-        ).also { element.classBody.declarations += it }
-    }
 }

j2k/newSrc/org/jetbrains/kotlin/j2k/expressions.kt

@@ -449,3 +449,17 @@ fun equalsExpression(left: JKExpression, right: JKExpression, symbolProvider: JK
         KtTokens.EQEQ,
         symbolProvider
     )
+
+fun JKClass.getOrCreateCompainonObject(): JKClass =
+    (declarationList.firstOrNull { it is JKClass && it.classKind == JKClass.ClassKind.COMPANION } as? JKClass)
+        ?: JKClassImpl(
+            JKNameIdentifierImpl(""),
+            JKInheritanceInfoImpl(emptyList(), emptyList()),
+            JKClass.ClassKind.COMPANION,
+            JKTypeParameterListImpl(),
+            JKClassBodyImpl(),
+            JKAnnotationListImpl(),
+            emptyList(),
+            Visibility.PUBLIC,
+            Modality.FINAL
+        ).also { classBody.declarations += it }