Leaking this: fix for 'this' in enum class #KT-15835 Fixed

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

@@ -19,6 +19,7 @@ import org.jetbrains.kotlin.idea.quickfix.AddModifierFix
 import org.jetbrains.kotlin.lexer.KtTokens
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.psi.psiUtil.containingClassOrObject
+import org.jetbrains.kotlin.psi.psiUtil.getChildrenOfType
 import org.jetbrains.kotlin.psi.psiUtil.getStrictParentOfType
 import org.jetbrains.kotlin.resolve.BindingContext.LEAKING_THIS
 import org.jetbrains.kotlin.resolve.DescriptorToSourceUtils
@@ -36,10 +37,17 @@ class LeakingThisInspection : AbstractKotlinInspection() {
                 if (leakingThisDescriptor.classOrObject != klass) continue@these
                 val description = when (leakingThisDescriptor) {
                     is NonFinalClass ->
-                        if (expression is KtThisExpression && expression.getStrictParentOfType<KtClassLiteralExpression>() == null)
-                            "Leaking 'this' in constructor of non-final class ${leakingThisDescriptor.klass.name}"
-                        else
+                        if (expression is KtThisExpression && expression.getStrictParentOfType<KtClassLiteralExpression>() == null) {
+                            if (klass.isEnum()) {
+                                val enumEntries = klass.body?.getChildrenOfType<KtEnumEntry>() ?: continue@these
+                                if (enumEntries.none { it.hasOverriddenMember() }) continue@these
+                                "Leaking 'this' in constructor of enum class ${leakingThisDescriptor.klass.name} (with overridable members)"
+                            } else {
+                                "Leaking 'this' in constructor of non-final class ${leakingThisDescriptor.klass.name}"
+                            }
+                        } else {
                             continue@these // Not supported yet
+                        }
                     is NonFinalProperty ->
                         "Accessing non-final property ${leakingThisDescriptor.property.name} in constructor"
                     is NonFinalFunction ->
@@ -75,6 +83,9 @@ class LeakingThisInspection : AbstractKotlinInspection() {
         }
     }
 
+    private fun KtEnumEntry.hasOverriddenMember(): Boolean {
+        return body?.getChildrenOfType<KtModifierListOwner>()?.any { it.hasModifier(KtTokens.OVERRIDE_KEYWORD) } == true
+    }
 
     companion object {
         private fun createMakeFinalFix(declaration: KtDeclaration?): IntentionWrapper? {

idea/testData/inspectionsLocal/leakingThis/enum.kt

@@ -0,0 +1,8 @@
+// PROBLEM: none
+enum class Foo {
+    ONE,
+    TWO;
+    val bar = Bar(<caret>this)
+}
+
+class Bar(val foo: Foo)

idea/testData/inspectionsLocal/leakingThis/enumEntryHasOverriddenMember.kt

@@ -0,0 +1,20 @@
+// PROBLEM: Leaking 'this' in constructor of enum class Foo (with overridable members)
+// FIX: none
+enum class Foo {
+    ONE {
+        override val x = 1
+    },
+    TWO {
+        override val x = 2
+    };
+
+    abstract val x: Int
+    val double = double(<caret>this)
+}
+
+fun double(foo: Foo) = foo.x * foo.x
+
+fun test() {
+    Foo.ONE.double
+    Foo.TWO.double
+}

idea/testData/inspectionsLocal/leakingThis/enumEntryHasOverriddenMember2.kt

@@ -0,0 +1,23 @@
+// PROBLEM: Leaking 'this' in constructor of enum class Foo (with overridable members)
+// FIX: none
+enum class Foo : Bar {
+    ONE {
+        override val x = 1
+    },
+    TWO {
+        override val x = 2
+    };
+
+    val double = double(<caret>this)
+}
+
+interface Bar {
+    val x: Int
+}
+
+fun double(foo: Foo) = foo.x * foo.x
+
+fun test() {
+    Foo.ONE.double
+    Foo.TWO.double
+}

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

@@ -2705,6 +2705,21 @@ public class LocalInspectionTestGenerated extends AbstractLocalInspectionTest {
             KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("idea/testData/inspectionsLocal/leakingThis"), Pattern.compile("^([\\w\\-_]+)\\.(kt|kts)$"), TargetBackend.ANY, true);
         }
 
+        @TestMetadata("enum.kt")
+        public void testEnum() throws Exception {
+            runTest("idea/testData/inspectionsLocal/leakingThis/enum.kt");
+        }
+
+        @TestMetadata("enumEntryHasOverriddenMember.kt")
+        public void testEnumEntryHasOverriddenMember() throws Exception {
+            runTest("idea/testData/inspectionsLocal/leakingThis/enumEntryHasOverriddenMember.kt");
+        }
+
+        @TestMetadata("enumEntryHasOverriddenMember2.kt")
+        public void testEnumEntryHasOverriddenMember2() throws Exception {
+            runTest("idea/testData/inspectionsLocal/leakingThis/enumEntryHasOverriddenMember2.kt");
+        }
+
         @TestMetadata("inClassLiteral.kt")
         public void testInClassLiteral() throws Exception {
             runTest("idea/testData/inspectionsLocal/leakingThis/inClassLiteral.kt");