From 6e41b236725eedc9bf35e1be2232ef21e58cc10f Mon Sep 17 00:00:00 2001
From: Bas Leijdekkers <basleijdekkers@gmail.com>
Date: Thu, 8 May 2025 17:54:09 +0200
Subject: [PATCH] [extract method with object] show error when variables are
 used in loop (IDEA-356602)

GitOrigin-RevId: e84bcf1f1d03819ca4b5c12b91fad72baf82fc27
---
 .../parameterObject/ParameterObjectUtils.kt    | 18 +++++++++++++++---
 .../IntroduceObjectFailedWithLoop.java         | 12 ++++++++++++
 .../ExtractMethodAndDuplicatesInplaceTest.kt   |  8 +++++++-
 3 files changed, 34 insertions(+), 4 deletions(-)
 create mode 100644 java/java-tests/testData/refactoring/extractMethodAndDuplicatesInplace/IntroduceObjectFailedWithLoop.java

diff --git a/java/java-impl-refactorings/src/com/intellij/refactoring/extractMethod/newImpl/parameterObject/ParameterObjectUtils.kt b/java/java-impl-refactorings/src/com/intellij/refactoring/extractMethod/newImpl/parameterObject/ParameterObjectUtils.kt
index 07eb51b9699c..6bead6d9489e 100644
--- a/java/java-impl-refactorings/src/com/intellij/refactoring/extractMethod/newImpl/parameterObject/ParameterObjectUtils.kt
+++ b/java/java-impl-refactorings/src/com/intellij/refactoring/extractMethod/newImpl/parameterObject/ParameterObjectUtils.kt
@@ -29,17 +29,29 @@ object ParameterObjectUtils {
   }
 
   private fun findAffectedReferences(variable: PsiVariable, scope: List<PsiElement>): List<PsiReferenceExpression>? {
-    val startingOffset = scope.last().textRange.endOffset
+    val parent = scope.first().parent
+    val beforeScope = scope.first().textRange.startOffset
+    val afterScope = scope.last().textRange.endOffset
     val references = ReferencesSearch.search(variable)
       .asIterable()
       .mapNotNull { it.element as? PsiReferenceExpression }
-      .filter { reference -> reference.textRange.startOffset >= startingOffset }
+      .filter { reference -> reference.textRange.startOffset >= afterScope || reference.textRange.endOffset <= beforeScope }
       .sortedBy { reference -> reference.textRange.startOffset }
+    val referencesBefore = references.filter { ref -> ref.textRange.endOffset <= beforeScope }
+    if (!referencesBefore.isEmpty()) {
+      val loop = PsiTreeUtil.getParentOfType(parent, PsiLoopStatement::class.java, true)
+      if (loop != null) {
+        val suspiciousLoop = referencesBefore.any { ref -> PsiTreeUtil.isAncestor(loop, ref, true) }
+        if (suspiciousLoop) return null
+      }
+    }
     val firstAssignment = references.find { reference -> PsiUtil.isAccessedForWriting(reference) } ?: return references
     val assignmentExpression = PsiTreeUtil.getParentOfType(firstAssignment, PsiAssignmentExpression::class.java)
     if (assignmentExpression == null) return null
     if (assignmentExpression.parent.parent != PsiTreeUtil.findCommonParent(assignmentExpression, scope.last())) return null
-    return references.filter { reference -> reference.textRange.endOffset <= assignmentExpression.textRange.endOffset } - firstAssignment
+    return references.filter { ref -> ref != firstAssignment
+                                      && ref.textRange.endOffset <= assignmentExpression.textRange.endOffset
+                                      && ref.textRange.startOffset >= afterScope }
   }
 
 }
\ No newline at end of file
diff --git a/java/java-tests/testData/refactoring/extractMethodAndDuplicatesInplace/IntroduceObjectFailedWithLoop.java b/java/java-tests/testData/refactoring/extractMethodAndDuplicatesInplace/IntroduceObjectFailedWithLoop.java
new file mode 100644
index 000000000000..0c6f9118dfab
--- /dev/null
+++ b/java/java-tests/testData/refactoring/extractMethodAndDuplicatesInplace/IntroduceObjectFailedWithLoop.java
@@ -0,0 +1,12 @@
+public class Test {
+
+  void test() {
+    double x = 0;
+    double y = 0;
+    while (x < 10) {
+      <selection>x = x + .1;
+      y = y - .1;</selection>
+    }
+    System.out.println("x: " + x + "; y: " + y);
+  }
+}
\ No newline at end of file
diff --git a/java/java-tests/testSrc/com/intellij/java/refactoring/ExtractMethodAndDuplicatesInplaceTest.kt b/java/java-tests/testSrc/com/intellij/java/refactoring/ExtractMethodAndDuplicatesInplaceTest.kt
index 7ac74935be94..9653ab2aa2f3 100644
--- a/java/java-tests/testSrc/com/intellij/java/refactoring/ExtractMethodAndDuplicatesInplaceTest.kt
+++ b/java/java-tests/testSrc/com/intellij/java/refactoring/ExtractMethodAndDuplicatesInplaceTest.kt
@@ -1,4 +1,4 @@
-// Copyright 2000-2023 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+// Copyright 2000-2025 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
 package com.intellij.java.refactoring
 
 import com.intellij.codeInsight.hint.HintManager
@@ -443,6 +443,12 @@ class ExtractMethodAndDuplicatesInplaceTest: LightJavaCodeInsightTestCase() {
     require(getActiveTemplate() != null)
   }
 
+  fun testIntroduceObjectFailedWithLoop(){
+    assertThrows(RefactoringErrorHintException::class.java) {
+      doTest()
+    }
+  }
+
   fun testIntroduceObjectFailedWithAssignment1(){
     assertThrows(RefactoringErrorHintException::class.java) {
       doTest()