Move variable declaration into when: don't report when property has 'return' or 'throw'

#KT-31999 Fixed

idea/src/org/jetbrains/kotlin/idea/inspections/MoveVariableDeclarationIntoWhenInspection.kt

@@ -21,6 +21,7 @@ import org.jetbrains.kotlin.idea.intentions.loopToCallChain.countUsages
 import org.jetbrains.kotlin.idea.intentions.loopToCallChain.previousStatement
 import org.jetbrains.kotlin.lexer.KtTokens
 import org.jetbrains.kotlin.psi.*
+import org.jetbrains.kotlin.psi.psiUtil.anyDescendantOfType
 import org.jetbrains.kotlin.psi.psiUtil.createSmartPointer
 import org.jetbrains.kotlin.psi.psiUtil.siblings
 import org.jetbrains.kotlin.psi.psiUtil.startOffset
@@ -31,6 +32,7 @@ class MoveVariableDeclarationIntoWhenInspection : AbstractKotlinInspection(), Cl
             val subjectExpression = expression.subjectExpression ?: return
             val property = expression.findDeclarationNear() ?: return
             if (!property.isOneLiner()) return
+            if (property.hasReturnOrThrowExpression()) return
 
             val action = property.action(expression)
             if (action == Action.NOTHING) return
@@ -75,6 +77,10 @@ private fun KtWhenExpression.findDeclarationNear(): KtProperty? {
     return previousProperty.takeIf { !it.isVar && it.hasInitializer() && it.nameIdentifier?.text == subjectExpression?.text }
 }
 
+private fun KtProperty.hasReturnOrThrowExpression(): Boolean {
+    return this.initializer?.anyDescendantOfType<KtExpression> { it is KtReturnExpression || it is KtThrowExpression } == true
+}
+
 private tailrec fun KtExpression.previousPropertyFromParent(): KtProperty? {
     val parentExpression = parent as? KtExpression ?: return null
     if (this != when (parentExpression) {

idea/testData/inspectionsLocal/moveVariableDeclarationIntoWhen/hasReturn.kt

@@ -0,0 +1,8 @@
+// PROBLEM: none
+fun test(str: String?): String? {
+    val <caret>some = str ?: return null
+    return when (some) {
+        "some" -> some
+        else -> ""
+    }
+}

idea/testData/inspectionsLocal/moveVariableDeclarationIntoWhen/hasReturn2.kt

@@ -0,0 +1,8 @@
+// PROBLEM: none
+fun test(str: String?): String? {
+    val <caret>some = if (str != null) str + str else return null
+    return when (some) {
+        "some" -> some
+        else -> ""
+    }
+}

idea/testData/inspectionsLocal/moveVariableDeclarationIntoWhen/hasThrow.kt

@@ -0,0 +1,8 @@
+// PROBLEM: none
+fun test(str: String?): String? {
+    val <caret>some = str ?: throw Exception()
+    return when (some) {
+        "some" -> some
+        else -> ""
+    }
+}

idea/testData/inspectionsLocal/moveVariableDeclarationIntoWhen/hasThrow2.kt

@@ -0,0 +1,8 @@
+// PROBLEM: none
+fun test(str: String?): String? {
+    val <caret>some = if (str != null) str + str else throw Exception()
+    return when (some) {
+        "some" -> some
+        else -> ""
+    }
+}

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

@@ -6093,6 +6093,26 @@ public class LocalInspectionTestGenerated extends AbstractLocalInspectionTest {
             KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("idea/testData/inspectionsLocal/moveVariableDeclarationIntoWhen"), Pattern.compile("^([\\w\\-_]+)\\.(kt|kts)$"), TargetBackend.ANY, true);
         }
 
+        @TestMetadata("hasReturn.kt")
+        public void testHasReturn() throws Exception {
+            runTest("idea/testData/inspectionsLocal/moveVariableDeclarationIntoWhen/hasReturn.kt");
+        }
+
+        @TestMetadata("hasReturn2.kt")
+        public void testHasReturn2() throws Exception {
+            runTest("idea/testData/inspectionsLocal/moveVariableDeclarationIntoWhen/hasReturn2.kt");
+        }
+
+        @TestMetadata("hasThrow.kt")
+        public void testHasThrow() throws Exception {
+            runTest("idea/testData/inspectionsLocal/moveVariableDeclarationIntoWhen/hasThrow.kt");
+        }
+
+        @TestMetadata("hasThrow2.kt")
+        public void testHasThrow2() throws Exception {
+            runTest("idea/testData/inspectionsLocal/moveVariableDeclarationIntoWhen/hasThrow2.kt");
+        }
+
         @TestMetadata("inBinaryExpression.kt")
         public void testInBinaryExpression() throws Exception {
             runTest("idea/testData/inspectionsLocal/moveVariableDeclarationIntoWhen/inBinaryExpression.kt");