Extract Function: Parenthesize binary expressions if operation reference starts with a new line

idea/src/org/jetbrains/kotlin/idea/refactoring/introduce/extractionEngine/extractorUtil.kt

@@ -31,12 +31,9 @@ import org.jetbrains.kotlin.idea.intentions.ConvertToExpressionBodyIntention
 import org.jetbrains.kotlin.idea.intentions.InfixCallToOrdinaryIntention
 import org.jetbrains.kotlin.idea.intentions.OperatorToFunctionIntention
 import org.jetbrains.kotlin.idea.intentions.RemoveExplicitTypeArgumentsIntention
-import org.jetbrains.kotlin.idea.refactoring.introduce.extractableSubstringInfo
+import org.jetbrains.kotlin.idea.refactoring.introduce.*
 import org.jetbrains.kotlin.idea.refactoring.introduce.extractionEngine.OutputValue.*
 import org.jetbrains.kotlin.idea.refactoring.introduce.extractionEngine.OutputValueBoxer.AsTuple
-import org.jetbrains.kotlin.idea.refactoring.introduce.getPhysicalTextRange
-import org.jetbrains.kotlin.idea.refactoring.introduce.replaceWith
-import org.jetbrains.kotlin.idea.refactoring.introduce.substringContextOrThis
 import org.jetbrains.kotlin.idea.util.IdeDescriptorRenderers
 import org.jetbrains.kotlin.idea.util.ShortenReferences
 import org.jetbrains.kotlin.idea.util.psi.patternMatching.*
@@ -466,6 +463,12 @@ fun ExtractionGeneratorConfiguration.generateDeclaration(
     fun adjustDeclarationBody(declaration: KtNamedDeclaration) {
         val body = declaration.getGeneratedBody()
 
+        (body.blockExpressionsOrSingle().singleOrNull() as? KtExpression)?.let {
+            if (it.mustBeParenthesizedInInitializerPosition()) {
+                it.replace(psiFactory.createExpressionByPattern("($0)", it))
+            }
+        }
+
         val jumpValue = descriptor.controlFlow.jumpOutputValue
         if (jumpValue != null) {
             val replacingReturn = psiFactory.createExpression(if (jumpValue.conditional) "return true" else "return")

idea/src/org/jetbrains/kotlin/idea/refactoring/introduce/introduceUtil.kt

@@ -22,10 +22,10 @@ import com.intellij.openapi.project.Project
 import com.intellij.openapi.util.Key
 import com.intellij.openapi.util.TextRange
 import com.intellij.psi.PsiElement
+import com.intellij.psi.PsiWhiteSpace
 import com.intellij.psi.util.PsiTreeUtil
 import org.jetbrains.kotlin.idea.codeInsight.CodeInsightUtils
 import org.jetbrains.kotlin.idea.core.refactoring.chooseContainerElementIfNecessary
-import org.jetbrains.kotlin.idea.core.refactoring.removeTemplateEntryBracesIfPossible
 import org.jetbrains.kotlin.idea.refactoring.KotlinRefactoringBundle
 import org.jetbrains.kotlin.idea.refactoring.KotlinRefactoringUtil
 import org.jetbrains.kotlin.idea.util.psi.patternMatching.KotlinPsiRange
@@ -83,7 +83,7 @@ fun selectElementsWithTargetParent(
     fun selectTargetContainer(elements: List<PsiElement>) {
         val physicalElements = elements.map { it.substringContextOrThis }
         val parent = PsiTreeUtil.findCommonParent(physicalElements)
-            ?: throw AssertionError("Should have at least one parent: ${physicalElements.joinToString("\n")}")
+                     ?: throw AssertionError("Should have at least one parent: ${physicalElements.joinToString("\n")}")
 
         val containers = getContainers(physicalElements, parent)
         if (containers.isEmpty()) {
@@ -196,4 +196,11 @@ fun ExtractableSubstringInfo.replaceWith(replacement: KtExpression): KtExpressio
 
         addedRefEntry.expression!!
     }
+}
+
+fun KtExpression.mustBeParenthesizedInInitializerPosition(): Boolean {
+    if (this !is KtBinaryExpression) return false
+
+    if (left?.mustBeParenthesizedInInitializerPosition() ?: false) return true
+    return PsiChildRange(left, operationReference).any { (it is PsiWhiteSpace) && it.textContains('\n') }
 }

idea/testData/refactoring/extractFunction/multiline/multilineBinaryExpression.kt

@@ -0,0 +1,6 @@
+fun foo(i: Int) { }
+
+fun test() {
+    foo(<selection>1
+        + 2</selection>)
+}

idea/testData/refactoring/extractFunction/multiline/multilineBinaryExpression.kt.after

@@ -0,0 +1,8 @@
+fun foo(i: Int) { }
+
+fun test() {
+    foo(i())
+}
+
+private fun i() = (1
+        + 2)

idea/testData/refactoring/extractFunction/multiline/multilineBinaryExpressionWithComments.kt

@@ -0,0 +1,6 @@
+fun foo(i: Int) { }
+
+fun test() {
+    foo(<selection>1 // abc
+        /*def*/ + 2</selection>)
+}

idea/testData/refactoring/extractFunction/multiline/multilineBinaryExpressionWithComments.kt.after

@@ -0,0 +1,8 @@
+fun foo(i: Int) { }
+
+fun test() {
+    foo(i())
+}
+
+private fun i() = (1 // abc
+        /*def*/ + 2)

idea/testData/refactoring/extractFunction/multiline/multilineNestedBinaryExpression1.kt

@@ -0,0 +1,6 @@
+fun foo(i: Int) { }
+
+fun test() {
+    foo(<selection>1
+        + 2 - 3</selection>)
+}

idea/testData/refactoring/extractFunction/multiline/multilineNestedBinaryExpression1.kt.after

@@ -0,0 +1,8 @@
+fun foo(i: Int) { }
+
+fun test() {
+    foo(i())
+}
+
+private fun i() = (1
+        + 2 - 3)

idea/testData/refactoring/extractFunction/multiline/multilineNestedBinaryExpression2.kt

@@ -0,0 +1,6 @@
+fun foo(i: Int) { }
+
+fun test() {
+    foo(<selection>1 + 2
+        - 3</selection>)
+}

idea/testData/refactoring/extractFunction/multiline/multilineNestedBinaryExpression2.kt.after

@@ -0,0 +1,8 @@
+fun foo(i: Int) { }
+
+fun test() {
+    foo(i())
+}
+
+private fun i() = (1 + 2
+        - 3)

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

@@ -2038,6 +2038,39 @@ public class ExtractionTestGenerated extends AbstractExtractionTest {
             }
         }
 
+        @TestMetadata("idea/testData/refactoring/extractFunction/multiline")
+        @TestDataPath("$PROJECT_ROOT")
+        @RunWith(JUnit3RunnerWithInners.class)
+        public static class Multiline extends AbstractExtractionTest {
+            public void testAllFilesPresentInMultiline() throws Exception {
+                KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("idea/testData/refactoring/extractFunction/multiline"), Pattern.compile("^(.+)\\.(kt|kts)$"), true);
+            }
+
+            @TestMetadata("multilineBinaryExpression.kt")
+            public void testMultilineBinaryExpression() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("idea/testData/refactoring/extractFunction/multiline/multilineBinaryExpression.kt");
+                doExtractFunctionTest(fileName);
+            }
+
+            @TestMetadata("multilineBinaryExpressionWithComments.kt")
+            public void testMultilineBinaryExpressionWithComments() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("idea/testData/refactoring/extractFunction/multiline/multilineBinaryExpressionWithComments.kt");
+                doExtractFunctionTest(fileName);
+            }
+
+            @TestMetadata("multilineNestedBinaryExpression1.kt")
+            public void testMultilineNestedBinaryExpression1() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("idea/testData/refactoring/extractFunction/multiline/multilineNestedBinaryExpression1.kt");
+                doExtractFunctionTest(fileName);
+            }
+
+            @TestMetadata("multilineNestedBinaryExpression2.kt")
+            public void testMultilineNestedBinaryExpression2() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("idea/testData/refactoring/extractFunction/multiline/multilineNestedBinaryExpression2.kt");
+                doExtractFunctionTest(fileName);
+            }
+        }
+
         @TestMetadata("idea/testData/refactoring/extractFunction/parameters")
         @TestDataPath("$PROJECT_ROOT")
         @RunWith(JUnit3RunnerWithInners.class)