Fold initializer & if to elvis: search for variable usage inside if first #KT-14889 Fixed

idea/src/org/jetbrains/kotlin/idea/intentions/FoldInitializerAndIfToElvisIntention.kt

@@ -19,6 +19,8 @@ package org.jetbrains.kotlin.idea.intentions
 import com.intellij.openapi.editor.Editor
 import com.intellij.openapi.util.TextRange
 import com.intellij.psi.PsiWhiteSpace
+import com.intellij.psi.search.LocalSearchScope
+import com.intellij.psi.search.searches.ReferencesSearch
 import org.jetbrains.kotlin.idea.caches.resolve.analyze
 import org.jetbrains.kotlin.idea.core.replaced
 import org.jetbrains.kotlin.idea.core.setType
@@ -27,10 +29,7 @@ import org.jetbrains.kotlin.idea.intentions.branchedTransformations.expressionCo
 import org.jetbrains.kotlin.idea.util.CommentSaver
 import org.jetbrains.kotlin.lexer.KtTokens
 import org.jetbrains.kotlin.psi.*
-import org.jetbrains.kotlin.psi.psiUtil.PsiChildRange
-import org.jetbrains.kotlin.psi.psiUtil.endOffset
-import org.jetbrains.kotlin.psi.psiUtil.siblings
-import org.jetbrains.kotlin.psi.psiUtil.startOffset
+import org.jetbrains.kotlin.psi.psiUtil.*
 import org.jetbrains.kotlin.resolve.lazy.BodyResolveMode
 import org.jetbrains.kotlin.types.typeUtil.isNothing
 import org.jetbrains.kotlin.types.typeUtil.makeNotNullable
@@ -107,21 +106,22 @@ class FoldInitializerAndIfToElvisIntention : SelfTargetingRangeIntention<KtIfExp
         } as? KtNameReferenceExpression ?: return null
 
         if (ifExpression.parent !is KtBlockExpression) return null
-        val prevStatement = ifExpression.siblings(forward = false, withItself = false)
-                                    .firstIsInstanceOrNull<KtExpression>() ?: return null
-        if (prevStatement !is KtVariableDeclaration) return null
+        val prevStatement = (ifExpression.siblings(forward = false, withItself = false)
+                                         .firstIsInstanceOrNull<KtExpression>() ?: return null) as? KtVariableDeclaration
+        prevStatement ?: return null
         if (prevStatement.nameAsName != value.getReferencedNameAsName()) return null
         val initializer = prevStatement.initializer ?: return null
         val then = ifExpression.then ?: return null
         val typeReference = (operationExpression as? KtIsExpression)?.typeReference
 
-        if (then is KtBlockExpression) {
-            val statement = then.statements.singleOrNull() ?: return null
-            return Data(initializer, prevStatement, statement, typeReference)
-        }
-        else {
-            return Data(initializer, prevStatement, then, typeReference)
+        val statement = if (then is KtBlockExpression) then.statements.singleOrNull() else then
+        statement ?: return null
+
+        if (ReferencesSearch.search(prevStatement, LocalSearchScope(statement)).findFirst() != null) {
+            return null
         }
+
+        return Data(initializer, prevStatement, statement, typeReference)
     }
 
     private fun PsiChildRange.withoutLastStatement(): PsiChildRange {

idea/testData/intentions/foldInitializerAndIfToElvis/UsedInside.kt

+// IS_APPLICABLE: false
+
+interface A {
+    val s: String
+}
+
+fun foo() = Any()
+
+fun test(): String {
+    val y = foo()
+    <caret>if (y !is A) return y.toString()
+    return y.s
+}
\ No newline at end of file

idea/testData/intentions/foldInitializerAndIfToElvis/UsedInsideInTemplate.kt

+// IS_APPLICABLE: false
+
+interface A {
+    val s: String
+}
+
+fun foo() = Any()
+
+fun test(): String {
+    val y = foo()
+    <caret>if (y !is A) return "Expected A: $y"
+    return y.s
+}
\ No newline at end of file

idea/tests/org/jetbrains/kotlin/idea/intentions/IntentionTestGenerated.java

@@ -7397,6 +7397,18 @@ public class IntentionTestGenerated extends AbstractIntentionTest {
             doTest(fileName);
         }
 
+        @TestMetadata("UsedInside.kt")
+        public void testUsedInside() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/foldInitializerAndIfToElvis/UsedInside.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("UsedInsideInTemplate.kt")
+        public void testUsedInsideInTemplate() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/foldInitializerAndIfToElvis/UsedInsideInTemplate.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("Var.kt")
         public void testVar() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/foldInitializerAndIfToElvis/Var.kt");