Extract Interface/Pull Up: Drop 'final' modifier when moving to an interface

#KT-15640 Fixed

idea/src/org/jetbrains/kotlin/idea/refactoring/pullUp/pullUpUtils.kt

@@ -18,7 +18,6 @@ package org.jetbrains.kotlin.idea.refactoring.pullUp
 
 import com.intellij.psi.PsiClass
 import com.intellij.psi.PsiMethod
-import com.intellij.psi.PsiNamedElement
 import org.jetbrains.kotlin.asJava.toLightClass
 import org.jetbrains.kotlin.descriptors.CallableMemberDescriptor
 import org.jetbrains.kotlin.descriptors.ClassDescriptor
@@ -59,6 +58,10 @@ fun KtNamedDeclaration.canMoveMemberToJavaClass(targetClass: PsiClass): Boolean
 }
 
 fun addMemberToTarget(targetMember: KtNamedDeclaration, targetClass: KtClassOrObject): KtNamedDeclaration {
+    if (targetClass is KtClass && targetClass.isInterface()) {
+        targetMember.removeModifier(KtTokens.FINAL_KEYWORD)
+    }
+
     if (targetMember is KtParameter) {
         val parameterList = (targetClass as KtClass).createPrimaryConstructorIfAbsent().valueParameterList!!
         val anchor = parameterList.parameters.firstOrNull { it.isVarArg || it.hasDefaultValue() }

idea/testData/refactoring/extractInterface/dropFinal.kt

@@ -0,0 +1,6 @@
+// NAME: I
+// SIBLING:
+class <caret>A {
+    // INFO: {checked: "true"}
+    final val one = 1
+}

idea/testData/refactoring/extractInterface/dropFinal.kt.after

@@ -0,0 +1,11 @@
+interface I {
+    // INFO: {checked: "true"}
+    val one: Int
+}
+
+// NAME: I
+// SIBLING:
+class A : I {
+    // INFO: {checked: "true"}
+    final override val one = 1
+}

idea/testData/refactoring/pullUp/k2k/dropFinal.kt

@@ -0,0 +1,6 @@
+interface I
+
+class <caret>A : I {
+    // INFO: {checked: "true"}
+    final val one = 1
+}

idea/testData/refactoring/pullUp/k2k/dropFinal.kt.after

@@ -0,0 +1,9 @@
+interface I {
+    // INFO: {checked: "true"}
+    val one: Int
+}
+
+class A : I {
+    // INFO: {checked: "true"}
+    final override val one = 1
+}

idea/tests/org/jetbrains/kotlin/idea/refactoring/introduce/ExtractionTestGenerated.java

@@ -4358,6 +4358,12 @@ public class ExtractionTestGenerated extends AbstractExtractionTest {
             doExtractInterfaceTest(fileName);
         }
 
+        @TestMetadata("dropFinal.kt")
+        public void testDropFinal() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/refactoring/extractInterface/dropFinal.kt");
+            doExtractInterfaceTest(fileName);
+        }
+
         @TestMetadata("specialName.kt")
         public void testSpecialName() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/testData/refactoring/extractInterface/specialName.kt");

idea/tests/org/jetbrains/kotlin/idea/refactoring/pullUp/PullUpTestGenerated.java

@@ -110,6 +110,12 @@ public class PullUpTestGenerated extends AbstractPullUpTest {
             doKotlinTest(fileName);
         }
 
+        @TestMetadata("dropFinal.kt")
+        public void testDropFinal() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/refactoring/pullUp/k2k/dropFinal.kt");
+            doKotlinTest(fileName);
+        }
+
         @TestMetadata("dropModifierWhenMovingSideOverride.kt")
         public void testDropModifierWhenMovingSideOverride() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/testData/refactoring/pullUp/k2k/dropModifierWhenMovingSideOverride.kt");