More accurate handling of Elvis in areParenthesesNecessary #KT-15227 Fixed

compiler/frontend/src/org/jetbrains/kotlin/psi/KtPsiUtil.java

@@ -503,7 +503,10 @@ public class KtPsiUtil {
         if (parentElement instanceof KtLabeledExpression) return false;
 
         // 'x ?: ...' case
-        if (parentElement instanceof KtBinaryExpression && parentOperation == KtTokens.ELVIS && currentInner == ((KtBinaryExpression) parentElement).getRight()) {
+        if (parentElement instanceof KtBinaryExpression &&
+            parentOperation == KtTokens.ELVIS &&
+            !(innerExpression instanceof KtBinaryExpression) &&
+            currentInner == ((KtBinaryExpression) parentElement).getRight()) {
             return false;
         }
 

idea/testData/intentions/branched/ifThenToElvis/comparisonInElse.kt

@@ -0,0 +1,9 @@
+// See KT-15227
+class My(val local: Boolean)
+
+class Your(val my: My?, val parent: Any?)
+
+fun foo(your: Your): Boolean {
+    val my = your.my
+    return <caret>if (my != null) my.local else your.parent != null
+}

idea/testData/intentions/branched/ifThenToElvis/comparisonInElse.kt.after

@@ -0,0 +1,9 @@
+// See KT-15227
+class My(val local: Boolean)
+
+class Your(val my: My?, val parent: Any?)
+
+fun foo(your: Your): Boolean {
+    val my = your.my
+    return my?.local ?: (your.parent != null)
+}

idea/testData/intentions/branched/ifThenToElvis/inspectionData/expected.xml

@@ -87,4 +87,12 @@
     <problem_class severity="WARNING" attribute_key="WARNING_ATTRIBUTES">If-Then foldable to '?:'</problem_class>
     <description>Replace 'if' expression with elvis expression</description>
   </problem>
+  <problem>
+    <file>comparisonInElse.kt</file>
+    <line>8</line>
+    <module>light_idea_test_case</module>
+    <entry_point TYPE="file" FQNAME="temp:///src/comparisonInElse.kt" />
+    <problem_class severity="WARNING" attribute_key="WARNING_ATTRIBUTES">If-Then foldable to '?:'</problem_class>
+    <description>Replace 'if' expression with elvis expression</description>
+  </problem>
 </problems>

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

@@ -1294,6 +1294,12 @@ public class IntentionTestGenerated extends AbstractIntentionTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("comparisonInElse.kt")
+            public void testComparisonInElse() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/branched/ifThenToElvis/comparisonInElse.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("conditionComparesNullWithNull.kt")
             public void testConditionComparesNullWithNull() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/branched/ifThenToElvis/conditionComparesNullWithNull.kt");