[kotlin] KTIJ-37276 ReplaceManualRangeWithIndicesCallsInspection: take names conflict into account

GitOrigin-RevId: e9a783709d4a0286def7842f6b98bdc071a3a92c

plugins/kotlin/code-insight/inspections-k2/tests/test/org/jetbrains/kotlin/idea/k2/inspections/tests/K2LocalInspectionTestGenerated.java

@@ -9702,6 +9702,26 @@ public abstract class K2LocalInspectionTestGenerated extends AbstractK2LocalInsp
             runTest("../../../idea/tests/testData/inspectionsLocal/replaceManualRangeWithIndicesCalls/complexReceiver.kt");
         }
 
+        @TestMetadata("elementNameCollision.kt")
+        public void testElementNameCollision() throws Exception {
+            runTest("../../../idea/tests/testData/inspectionsLocal/replaceManualRangeWithIndicesCalls/elementNameCollision.kt");
+        }
+
+        @TestMetadata("elementNameCollisionMultiple.kt")
+        public void testElementNameCollisionMultiple() throws Exception {
+            runTest("../../../idea/tests/testData/inspectionsLocal/replaceManualRangeWithIndicesCalls/elementNameCollisionMultiple.kt");
+        }
+
+        @TestMetadata("elementNameCollisionNestedLoop.kt")
+        public void testElementNameCollisionNestedLoop() throws Exception {
+            runTest("../../../idea/tests/testData/inspectionsLocal/replaceManualRangeWithIndicesCalls/elementNameCollisionNestedLoop.kt");
+        }
+
+        @TestMetadata("elementNameCollisionParameter.kt")
+        public void testElementNameCollisionParameter() throws Exception {
+            runTest("../../../idea/tests/testData/inspectionsLocal/replaceManualRangeWithIndicesCalls/elementNameCollisionParameter.kt");
+        }
+
         @TestMetadata("forNotTarget.kt")
         public void testForNotTarget() throws Exception {
             runTest("../../../idea/tests/testData/inspectionsLocal/replaceManualRangeWithIndicesCalls/forNotTarget.kt");

plugins/kotlin/code-insight/inspections-shared/src/org/jetbrains/kotlin/idea/codeInsight/inspections/shared/ReplaceManualRangeWithIndicesCallsInspection.kt

@@ -9,6 +9,9 @@ import com.intellij.psi.search.searches.ReferencesSearch
 import org.jetbrains.kotlin.analysis.api.KaSession
 import org.jetbrains.kotlin.analysis.api.resolution.successfulVariableAccessCall
 import org.jetbrains.kotlin.analysis.api.types.KaType
+import org.jetbrains.kotlin.idea.base.codeInsight.KotlinDeclarationNameValidator
+import org.jetbrains.kotlin.idea.base.codeInsight.KotlinNameSuggester
+import org.jetbrains.kotlin.idea.base.codeInsight.KotlinNameSuggestionProvider
 import org.jetbrains.kotlin.idea.base.psi.replaced
 import org.jetbrains.kotlin.idea.base.psi.safeDeparenthesize
 import org.jetbrains.kotlin.idea.base.resources.KotlinBundle
@@ -51,6 +54,7 @@ class ReplaceManualRangeWithIndicesCallsInspection : AbstractRangeInspection<Rep
         val explicitReceiver: KtExpression?,
         val suggestElementLoop: Boolean,
         val implicitReceiverInfo: ImplicitReceiverInfo?,
+        val suggestedElementName: String?,
     )
 
     override fun getProblemDescription(
@@ -79,7 +83,7 @@ class ReplaceManualRangeWithIndicesCallsInspection : AbstractRangeInspection<Rep
 
     override fun KaSession.prepareContext(range: RangeExpression): Context? {
         val (_, right) = range.arguments
-        
+
         // Must end with a size/length call
         val sizeCall = right?.let { rightBound(range.type, it) } ?: return null
         val explicitReceiver = (sizeCall as? KtQualifiedExpression)?.receiverExpression
@@ -87,7 +91,20 @@ class ReplaceManualRangeWithIndicesCallsInspection : AbstractRangeInspection<Rep
         val suggestElementLoop = shouldSuggestElementLoop(range, explicitReceiver)
         val implicitReceiverInfo = if (explicitReceiver == null) sizeCall.getImplicitReceiverInfo() else null
 
-        return Context(explicitReceiver, suggestElementLoop, implicitReceiverInfo)
+        // Pre-compute a unique element name for the loop transformation
+        val suggestedElementName = if (suggestElementLoop) {
+            val forExpression = findContainingForLoop(range)
+            forExpression?.loopParameter?.let { loopParameter ->
+                val nameValidator = KotlinDeclarationNameValidator(
+                    loopParameter,
+                    true,
+                    KotlinNameSuggestionProvider.ValidatorTarget.VARIABLE,
+                )
+                KotlinNameSuggester.suggestNameByName("element") { nameValidator.validate(it) }
+            }
+        } else null
+
+        return Context(explicitReceiver, suggestElementLoop, implicitReceiverInfo, suggestedElementName)
     }
 
     private fun KaSession.rightBound(type: RangeKtExpressionType, expression: KtExpression): KtExpression? {
@@ -245,13 +262,14 @@ class ReplaceManualRangeWithIndicesCallsInspection : AbstractRangeInspection<Rep
             val forExpression = element.getStrictParentOfType<KtForExpression>() ?: return
             val loopParameter = forExpression.loopParameter ?: return
             val loopRange = forExpression.loopRange ?: return
+            val elementName = context.suggestedElementName ?: return
 
             val collection = resolveCollectionExpression(project)
 
             // Try a single usage first
             val singleUsageInfo = LoopToCollectionTransformUtils.findSingleArrayAccessUsage(loopParameter)
             if (singleUsageInfo != null) {
-                LoopToCollectionTransformUtils.transformLoop(project, listOf(singleUsageInfo), loopParameter, loopRange, collection)
+                LoopToCollectionTransformUtils.transformLoop(project, listOf(singleUsageInfo), loopParameter, loopRange, collection, elementName)
                 return
             }
 
@@ -267,7 +285,7 @@ class ReplaceManualRangeWithIndicesCallsInspection : AbstractRangeInspection<Rep
             }
 
             if (usageInfos.isNotEmpty()) {
-                LoopToCollectionTransformUtils.transformLoop(project, usageInfos, loopParameter, loopRange, collection)
+                LoopToCollectionTransformUtils.transformLoop(project, usageInfos, loopParameter, loopRange, collection, elementName)
             }
         }
 

plugins/kotlin/code-insight/utils/src/org/jetbrains/kotlin/idea/codeinsight/utils/LoopToCollectionTransformUtils.kt

@@ -30,7 +30,7 @@ object LoopToCollectionTransformUtils {
 
     /**
      * Finds the usage pattern for a loop parameter where it's used as an array index exactly once.
-     * 
+     *
      * @param loopParameter the loop parameter (e.g., `i` in `for (i in 0..<size)`)
      * @return LoopUsageInfo if the parameter is used exactly once as an array index, null otherwise
      */
@@ -38,38 +38,41 @@ object LoopToCollectionTransformUtils {
         val paramElement = loopParameter.originalElement ?: return null
         val usageElement = ReferencesSearch.search(paramElement).findAll().singleOrNull()?.element ?: return null
         val arrayAccessElement = usageElement.parents.match(KtContainerNode::class, last = KtArrayAccessExpression::class) ?: return null
-        
+
         return LoopUsageInfo(paramElement as KtParameter, usageElement, arrayAccessElement)
     }
 
     /**
      * Transforms an index-based loop to a collection-based loop with multiple array access usages by:
-     * 1. Replacing the loop parameter with "element" 
+     * 1. Replacing the loop parameter with the provided element name
      * 2. Replacing all array access expressions with direct element references
      * 3. Replacing the loop range with the collection expression
-     * 
+     *
      * @param project the current project
      * @param usageInfos information about all loop usage patterns
      * @param loopParameter the original loop parameter
      * @param loopRange the original loop range
      * @param newLoopRange the new collection expression to iterate over
+     * @param elementName the name for the new loop variable (should be pre-validated to avoid conflicts)
      */
     fun transformLoop(
         project: Project,
         usageInfos: List<LoopUsageInfo>,
         loopParameter: KtParameter,
         loopRange: KtExpression,
-        newLoopRange: KtExpression
+        newLoopRange: KtExpression,
+        elementName: String
     ) {
         val factory = KtPsiFactory(project)
-        val newParameter = factory.createLoopParameter("element")
-        val newReferenceExpression = factory.createExpression("element")
-        
+
+        val newParameter = factory.createLoopParameter(elementName)
+        val newReferenceExpression = factory.createExpression(elementName)
+
         // Replace all array access expressions with direct element references
         usageInfos.forEach { usageInfo ->
             usageInfo.arrayAccessElement.replace(newReferenceExpression.copy())
         }
-        
+
         loopParameter.replace(newParameter)
         loopRange.replace(newLoopRange)
     }

plugins/kotlin/idea/tests/test/org/jetbrains/kotlin/idea/inspections/LocalInspectionTestGenerated.java

@@ -14386,6 +14386,26 @@ public abstract class LocalInspectionTestGenerated extends AbstractK1LocalInspec
             runTest("testData/inspectionsLocal/replaceManualRangeWithIndicesCalls/complexReceiver.kt");
         }
 
+        @TestMetadata("elementNameCollision.kt")
+        public void testElementNameCollision() throws Exception {
+            runTest("testData/inspectionsLocal/replaceManualRangeWithIndicesCalls/elementNameCollision.kt");
+        }
+
+        @TestMetadata("elementNameCollisionMultiple.kt")
+        public void testElementNameCollisionMultiple() throws Exception {
+            runTest("testData/inspectionsLocal/replaceManualRangeWithIndicesCalls/elementNameCollisionMultiple.kt");
+        }
+
+        @TestMetadata("elementNameCollisionNestedLoop.kt")
+        public void testElementNameCollisionNestedLoop() throws Exception {
+            runTest("testData/inspectionsLocal/replaceManualRangeWithIndicesCalls/elementNameCollisionNestedLoop.kt");
+        }
+
+        @TestMetadata("elementNameCollisionParameter.kt")
+        public void testElementNameCollisionParameter() throws Exception {
+            runTest("testData/inspectionsLocal/replaceManualRangeWithIndicesCalls/elementNameCollisionParameter.kt");
+        }
+
         @TestMetadata("forNotTarget.kt")
         public void testForNotTarget() throws Exception {
             runTest("testData/inspectionsLocal/replaceManualRangeWithIndicesCalls/forNotTarget.kt");

plugins/kotlin/idea/tests/testData/inspectionsLocal/replaceManualRangeWithIndicesCalls/elementNameCollision.kt

@@ -0,0 +1,9 @@
+// WITH_STDLIB
+// IGNORE_K1
+fun test() {
+    val element = mutableListOf<String>("hello", "world")
+    for (i in 0 unt<caret>il element.size) {
+        element[i].length
+        element.size
+    }
+}

plugins/kotlin/idea/tests/testData/inspectionsLocal/replaceManualRangeWithIndicesCalls/elementNameCollision.kt.after

@@ -0,0 +1,9 @@
+// WITH_STDLIB
+// IGNORE_K1
+fun test() {
+    val element = mutableListOf<String>("hello", "world")
+    for (element1 in element) {
+        element1.length
+        element.size
+    }
+}

plugins/kotlin/idea/tests/testData/inspectionsLocal/replaceManualRangeWithIndicesCalls/elementNameCollisionMultiple.kt

@@ -0,0 +1,10 @@
+// WITH_STDLIB
+// IGNORE_K1
+fun test() {
+    val element = "first"
+    val element1 = "second"
+    val list = mutableListOf<String>("hello", "world")
+    for (i in 0 unt<caret>il list.size) {
+        list[i].length
+    }
+}

plugins/kotlin/idea/tests/testData/inspectionsLocal/replaceManualRangeWithIndicesCalls/elementNameCollisionMultiple.kt.after

@@ -0,0 +1,10 @@
+// WITH_STDLIB
+// IGNORE_K1
+fun test() {
+    val element = "first"
+    val element1 = "second"
+    val list = mutableListOf<String>("hello", "world")
+    for (element2 in list) {
+        element2.length
+    }
+}

plugins/kotlin/idea/tests/testData/inspectionsLocal/replaceManualRangeWithIndicesCalls/elementNameCollisionNestedLoop.kt

@@ -0,0 +1,10 @@
+// WITH_STDLIB
+// IGNORE_K1
+fun test() {
+    val outer = listOf(listOf("a", "b"), listOf("c", "d"))
+    for (element in outer) {
+        for (j in 0 unt<caret>il element.size) {
+            element[j].length
+        }
+    }
+}

plugins/kotlin/idea/tests/testData/inspectionsLocal/replaceManualRangeWithIndicesCalls/elementNameCollisionNestedLoop.kt.after

@@ -0,0 +1,10 @@
+// WITH_STDLIB
+// IGNORE_K1
+fun test() {
+    val outer = listOf(listOf("a", "b"), listOf("c", "d"))
+    for (element in outer) {
+        for (element1 in element) {
+            element1.length
+        }
+    }
+}

plugins/kotlin/idea/tests/testData/inspectionsLocal/replaceManualRangeWithIndicesCalls/elementNameCollisionParameter.kt

@@ -0,0 +1,8 @@
+// WITH_STDLIB
+// IGNORE_K1
+fun test(element: String, list: List<String>) {
+    for (i in 0 unt<caret>il list.size) {
+        list[i].length
+        element.length
+    }
+}

plugins/kotlin/idea/tests/testData/inspectionsLocal/replaceManualRangeWithIndicesCalls/elementNameCollisionParameter.kt.after

@@ -0,0 +1,8 @@
+// WITH_STDLIB
+// IGNORE_K1
+fun test(element: String, list: List<String>) {
+    for (element1 in list) {
+        element1.length
+        element.length
+    }
+}