From f1a638e7ecaa21842131d49b14b4518649e59c76 Mon Sep 17 00:00:00 2001
From: "Stuebinger, Bernd" <stuebingerb@mediamarktsaturn.com>
Date: Wed, 7 Sep 2022 11:24:43 +0200
Subject: [PATCH] Properly handle sealed classes with Kotlin 1.7 and JDK 17

---
 .../kotlin/io/mockk/proxy/jvm/ProxyMaker.kt       | 15 +++++++++++----
 .../kotlin/io/mockk/it/SealedClassTest.kt         |  3 ---
 .../kotlin/io/mockk/it/SealedInterfaceTest.kt     |  3 ---
 3 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/modules/mockk-agent/src/jvmMain/kotlin/io/mockk/proxy/jvm/ProxyMaker.kt b/modules/mockk-agent/src/jvmMain/kotlin/io/mockk/proxy/jvm/ProxyMaker.kt
index 39c7a5fec..0a05d3536 100644
--- a/modules/mockk-agent/src/jvmMain/kotlin/io/mockk/proxy/jvm/ProxyMaker.kt
+++ b/modules/mockk-agent/src/jvmMain/kotlin/io/mockk/proxy/jvm/ProxyMaker.kt
@@ -99,18 +99,25 @@ internal class ProxyMaker(
         clazz: Class<T>,
         interfaces: Array<Class<*>>
     ): Class<T> {
-        return if (Modifier.isFinal(clazz.modifiers)) {
+        val kClass = clazz.kotlin
+        return if (kClass.isFinal) {
             log.trace("Taking instance of $clazz itself because it is final.")
             clazz
-        } else if (interfaces.isEmpty() && !Modifier.isAbstract(clazz.modifiers) && inliner != null) {
+        } else if (interfaces.isEmpty() && !kClass.isAbstract && inliner != null) {
             log.trace("Taking instance of $clazz itself because it is not abstract and no additional interfaces specified.")
             clazz
+        } else if (kClass.isSealed) {
+            log.trace("Taking instance of subclass of $clazz because it is sealed.")
+            kClass.sealedSubclasses.firstNotNullOfOrNull {
+                @Suppress("UNCHECKED_CAST")
+                subclass(it.java, interfaces) as Class<T>
+            } ?: error("Unable to create proxy for sealed class $clazz, available subclasses: ${kClass.sealedSubclasses}")
         } else {
             log.trace(
                 "Building subclass proxy for $clazz with " +
                         "additional interfaces ${interfaces.toList()}"
             )
-            subclasser.subclass<T>(clazz, interfaces)
+            subclasser.subclass(clazz, interfaces)
         }
     }
 
@@ -143,7 +150,7 @@ internal class ProxyMaker(
             val defaultConstructor = cls.getDeclaredConstructor()
             try {
                 defaultConstructor.isAccessible = true
-            } catch (ex: Exception) {
+            } catch (ignored: Exception) {
                 // skip
             }
 
diff --git a/modules/mockk/src/commonTest/kotlin/io/mockk/it/SealedClassTest.kt b/modules/mockk/src/commonTest/kotlin/io/mockk/it/SealedClassTest.kt
index f48c8b1f4..efa39cab2 100644
--- a/modules/mockk/src/commonTest/kotlin/io/mockk/it/SealedClassTest.kt
+++ b/modules/mockk/src/commonTest/kotlin/io/mockk/it/SealedClassTest.kt
@@ -2,7 +2,6 @@ package io.mockk.it
 
 import io.mockk.every
 import io.mockk.mockk
-import kotlin.test.Ignore
 import kotlin.test.Test
 import kotlin.test.assertEquals
 
@@ -10,7 +9,6 @@ import kotlin.test.assertEquals
 class SealedClassTest {
 
     @Test
-    @Ignore("Fails on JDK17+ https://github.com/mockk/mockk/issues/832")
     fun serviceReturnsSealedClassImpl() {
         val factory = mockk<Factory> {
             every { create() } returns Leaf(1)
@@ -22,7 +20,6 @@ class SealedClassTest {
     }
 
     @Test
-    @Ignore("Fails on JDK17+ https://github.com/mockk/mockk/issues/832")
     fun serviceAnswersSealedClassImpl() {
         val factory = mockk<Factory> {
             every { create() } answers { Leaf(1) }
diff --git a/modules/mockk/src/commonTest/kotlin/io/mockk/it/SealedInterfaceTest.kt b/modules/mockk/src/commonTest/kotlin/io/mockk/it/SealedInterfaceTest.kt
index 4abe70221..91f727abf 100644
--- a/modules/mockk/src/commonTest/kotlin/io/mockk/it/SealedInterfaceTest.kt
+++ b/modules/mockk/src/commonTest/kotlin/io/mockk/it/SealedInterfaceTest.kt
@@ -3,14 +3,12 @@ package io.mockk.it
 import io.mockk.every
 import io.mockk.mockk
 import kotlin.test.Test
-import kotlin.test.Ignore
 import kotlin.test.assertEquals
 
 
 class SealedInterfaceTest {
 
     @Test
-    @Ignore("Fails on JDK17+ https://github.com/mockk/mockk/issues/832")
     fun serviceReturnsSealedClassImpl() {
         val factory = mockk<Factory> {
             every { create() } returns Leaf(1)
@@ -22,7 +20,6 @@ class SealedInterfaceTest {
     }
 
     @Test
-    @Ignore("Fails on JDK17+ https://github.com/mockk/mockk/issues/832")
     fun serviceAnswersSealedClassImpl() {
         val factory = mockk<Factory> {
             every { create() } answers { Leaf(1) }