Rename: Respect naming conventions in automatic variable rename

#KT-7851 Fixed

ChangeLog.md

@@ -171,6 +171,9 @@
 
 #### Refactorings
 
+###### New features
+- [`KT-7851`](https://youtrack.jetbrains.com/issue/KT-7851) Respect naming conventions in automatic variable rename
+
 ###### Issues fixed
 - [`KT-9156`](https://youtrack.jetbrains.com/issue/KT-9156) Quote non-identifier names in Kotlin references
 - [`KT-9157`](https://youtrack.jetbrains.com/issue/KT-9157) Fixed in-place rename of Kotlin expression referring Java declaration

idea/src/org/jetbrains/kotlin/idea/refactoring/rename/AutomaticVariableRenamer.kt

@@ -21,6 +21,8 @@ import com.intellij.openapi.util.text.StringUtil
 import com.intellij.psi.PsiClass
 import com.intellij.psi.PsiElement
 import com.intellij.psi.PsiNamedElement
+import com.intellij.psi.PsiVariable
+import com.intellij.psi.codeStyle.JavaCodeStyleManager
 import com.intellij.psi.util.PsiTreeUtil
 import com.intellij.refactoring.JavaRefactoringSettings
 import com.intellij.refactoring.RefactoringBundle
@@ -28,6 +30,7 @@ import com.intellij.refactoring.rename.naming.AutomaticRenamer
 import com.intellij.refactoring.rename.naming.AutomaticRenamerFactory
 import com.intellij.usageView.UsageInfo
 import org.jetbrains.kotlin.asJava.toLightClass
+import org.jetbrains.kotlin.asJava.toLightElements
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.descriptors.ClassDescriptor
 import org.jetbrains.kotlin.descriptors.VariableDescriptor
@@ -39,6 +42,7 @@ import org.jetbrains.kotlin.resolve.descriptorUtil.builtIns
 import org.jetbrains.kotlin.resolve.lazy.NoDescriptorForDeclarationException
 import org.jetbrains.kotlin.resolve.source.PsiSourceElement
 import org.jetbrains.kotlin.types.KotlinType
+import org.jetbrains.kotlin.utils.addToStdlib.firstIsInstanceOrNull
 import java.util.*
 
 class AutomaticVariableRenamer(
@@ -85,19 +89,37 @@ class AutomaticVariableRenamer(
     override fun entityName() = RefactoringBundle.message("entity.name.variable")
 
     override fun nameToCanonicalName(name: String, element: PsiNamedElement): String? {
+        if (element !is KtNamedDeclaration) return name
+
+        val psiVariable = element.toLightElements().firstIsInstanceOrNull<PsiVariable>()
+        val propertyName = if (psiVariable != null) {
+            val codeStyleManager = JavaCodeStyleManager.getInstance(psiVariable.project)
+            codeStyleManager.variableNameToPropertyName(name, codeStyleManager.getVariableKind(psiVariable))
+        }
+        else name
+
         if (element in toUnpluralize) {
-            val singular = StringUtil.unpluralize(name)
+            val singular = StringUtil.unpluralize(propertyName)
             if (singular != null) return singular
             toUnpluralize.remove(element)
         }
-        return name
+        return propertyName
     }
 
     override fun canonicalNameToName(canonicalName: String, element: PsiNamedElement): String? {
+        if (element !is KtNamedDeclaration) return canonicalName
+
+        val psiVariable = element.toLightElements().firstIsInstanceOrNull<PsiVariable>()
+        val varName = if (psiVariable != null) {
+            val codeStyleManager = JavaCodeStyleManager.getInstance(psiVariable.project)
+            codeStyleManager.propertyNameToVariableName(canonicalName, codeStyleManager.getVariableKind(psiVariable))
+        }
+        else canonicalName
+
         return if (element in toUnpluralize)
-            StringUtil.pluralize(canonicalName)
+            StringUtil.pluralize(varName)
         else
-            canonicalName
+            varName
     }
 
     companion object {

idea/testData/refactoring/rename/automaticRenamer/after/main.kt

@@ -1,10 +1,10 @@
 open class Bar : Throwable()
 
-val bar: Bar = Bar()
+val BAR: Bar = Bar()
-val bar1: Bar = Bar()
+val BAR_1: Bar = Bar()
 
-val bars: List<Bar> = listOf()
+val BARs: List<Bar> = listOf()
-val foos1: Array<Bar> = array()
+val FOOS_1: Array<Bar> = array()
 
 fun main(args: Array<String>) {
     val bar: Bar = Bar()

idea/testData/refactoring/rename/automaticRenamerForJavaClass/after/usage.kt

@@ -2,5 +2,5 @@ class BarImpl : Bar()
 
 object BarObj : Bar()
 
-val bar: Bar = Bar()
+val BAR: Bar = Bar()
-val bars: Array<Bar> = throw Error()
+val BARs: Array<Bar> = throw Error()

idea/testData/refactoring/rename/renameClassWithAutoVarConventions/after/test.kt

@@ -0,0 +1,13 @@
+package test
+
+class Bar {
+
+}
+
+val SOME_BAR: Bar = Bar()
+val BAR: Bar = Bar()
+
+val SOME___BAR: Bar = Bar()
+val BAR: Bar = Bar()
+
+val SOME_BAR: Bar = Bar()

idea/testData/refactoring/rename/renameClassWithAutoVarConventions/before/test.kt

@@ -0,0 +1,13 @@
+package test
+
+class Foo {
+
+}
+
+val SOME_FOO: Foo = Foo()
+val FOO: Foo = Foo()
+
+val some_foo: Foo = Foo()
+val foo: Foo = Foo()
+
+val SomeFoo: Foo = Foo()

idea/testData/refactoring/rename/renameClassWithAutoVarConventions/renameClassWithAutoVarConventions.test

@@ -0,0 +1,6 @@
+{
+  "type": "KOTLIN_CLASS",
+  "mainFile": "test.kt",
+  "classId": "test/Foo",
+  "newName": "Bar"
+}

idea/tests/org/jetbrains/kotlin/idea/refactoring/rename/RenameTestGenerated.java

@@ -125,6 +125,12 @@ public class RenameTestGenerated extends AbstractRenameTest {
         doTest(fileName);
     }
 
+    @TestMetadata("renameClassWithAutoVarConventions/renameClassWithAutoVarConventions.test")
+    public void testRenameClassWithAutoVarConventions_RenameClassWithAutoVarConventions() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("idea/testData/refactoring/rename/renameClassWithAutoVarConventions/renameClassWithAutoVarConventions.test");
+        doTest(fileName);
+    }
+
     @TestMetadata("renameCompareTo/compareTo.test")
     public void testRenameCompareTo_CompareTo() throws Exception {
         String fileName = KotlinTestUtils.navigationMetadata("idea/testData/refactoring/rename/renameCompareTo/compareTo.test");