[Gradle][MPP] Implement assertAllImplementationsAlsoImplement assertion function

^KT-52726 Verification Pending

libraries/tools/kotlin-gradle-plugin/src/functionalTest/kotlin/org/jetbrains/kotlin/gradle/mpp/InternalKotlinCompilationTest.kt

@@ -7,23 +7,14 @@
 
 package org.jetbrains.kotlin.gradle.mpp
 
+import org.jetbrains.kotlin.gradle.assertAllImplementationsAlsoImplement
 import org.jetbrains.kotlin.gradle.plugin.KotlinCompilation
 import org.jetbrains.kotlin.gradle.plugin.mpp.InternalKotlinCompilation
-import org.jetbrains.kotlin.gradle.reflections
 import org.junit.Test
-import kotlin.reflect.full.isSubclassOf
-import kotlin.test.fail
 
 class InternalKotlinSourceSetTest {
     @Test
     fun `test - all implementations of KotlinCompilation - implement InternalKotlinCompilation`() {
-        val subtypesOfKotlinSourceSet = reflections.getSubTypesOf(KotlinCompilation::class.java)
+        assertAllImplementationsAlsoImplement(KotlinCompilation::class, InternalKotlinCompilation::class)
-        subtypesOfKotlinSourceSet
-            .filter { subtype -> !subtype.isInterface }
-            .forEach { implementation ->
-                if (!implementation.kotlin.isSubclassOf(InternalKotlinCompilation::class)) {
-                    fail("$implementation does not implement ${InternalKotlinCompilation::class}")
-                }
-            }
     }
 }

libraries/tools/kotlin-gradle-plugin/src/functionalTest/kotlin/org/jetbrains/kotlin/gradle/reflectionUtils.kt

@@ -6,5 +6,21 @@
 package org.jetbrains.kotlin.gradle
 
 import org.reflections.Reflections
+import kotlin.reflect.KClass
+import kotlin.reflect.full.isSubclassOf
+import kotlin.test.fail
 
 val reflections = Reflections("org.jetbrains")
+
+fun assertAllImplementationsAlsoImplement(
+    baseInterface: KClass<*>,
+    requiredInterface: KClass<*>
+) {
+    reflections.getSubTypesOf(baseInterface.java)
+        .filter { subtype -> !subtype.isInterface }
+        .forEach { implementation ->
+            if (!implementation.kotlin.isSubclassOf(requiredInterface)) {
+                fail("${implementation.kotlin} does not implement $requiredInterface")
+            }
+        }
+}

libraries/tools/kotlin-gradle-plugin/src/functionalTest/kotlin/org/jetbrains/kotlin/gradle/sources/InternalKotlinSourceSetTest.kt

@@ -7,6 +7,7 @@
 
 package org.jetbrains.kotlin.gradle.sources
 
+import org.jetbrains.kotlin.gradle.assertAllImplementationsAlsoImplement
 import org.jetbrains.kotlin.gradle.buildProjectWithMPP
 import org.jetbrains.kotlin.gradle.dsl.multiplatformExtension
 import org.jetbrains.kotlin.gradle.plugin.KotlinCompilation
@@ -14,6 +15,7 @@ import org.jetbrains.kotlin.gradle.plugin.KotlinSourceSet
 import org.jetbrains.kotlin.gradle.plugin.sources.InternalKotlinSourceSet
 import org.jetbrains.kotlin.gradle.plugin.sources.internal
 import org.jetbrains.kotlin.gradle.reflections
+import org.junit.jupiter.api.assertAll
 import kotlin.reflect.full.isSubclassOf
 import kotlin.test.Test
 import kotlin.test.assertEquals
@@ -22,14 +24,7 @@ import kotlin.test.fail
 class InternalKotlinSourceSetTest {
     @Test
     fun `test - all implementations of KotlinSourceSet - implement InternalKotlinSourceSet`() {
-        val subtypesOfKotlinSourceSet = reflections.getSubTypesOf(KotlinSourceSet::class.java)
+        assertAllImplementationsAlsoImplement(KotlinSourceSet::class, InternalKotlinSourceSet::class)
-        subtypesOfKotlinSourceSet
-            .filter { subtype -> !subtype.isInterface }
-            .forEach { implementation ->
-                if (!implementation.kotlin.isSubclassOf(InternalKotlinSourceSet::class)) {
-                    fail("$implementation does not implement ${InternalKotlinSourceSet::class}")
-                }
-            }
     }
 
     @Test