Fixed enum schema builder not handling nullable types.

Author: Wicpar

src/main/kotlin/com/papsign/ktor/openapigen/schema/builder/provider/DefaultEnumSchemaProvider.kt

@@ -13,7 +13,7 @@ import kotlin.reflect.jvm.jvmErasure
 object DefaultEnumSchemaProvider: SchemaBuilderProviderModule, OpenAPIGenModuleExtension {
 
     private object Builder: SchemaBuilder {
-        override val superType: KType = getKType<Enum<*>>()
+        override val superType: KType = getKType<Enum<*>?>()
 
         override fun build(
             type: KType,

src/test/kotlin/GeneralBehaviorTest.kt

@@ -46,6 +46,7 @@ class GeneralBehaviorTest {
         assert(!getKType<FloatArray>().isSubtypeOf(getKType<Array<Any>>()))
         assert(!getKType<Array<Any>>().isSubtypeOf(getKType<Iterable<Any>>()))
         assert(getKType<List<Any>>().isSubtypeOf(getKType<Iterable<Any>>()))
+        assert(getKType<List<Any>>().isSubtypeOf(getKType<Iterable<Any?>>()))
     }
 
     @Test
@@ -60,4 +61,19 @@ class GeneralBehaviorTest {
     fun testEnumSubtypes() {
         assert(getKType<TestEnum>().isSubtypeOf(getKType<Enum<*>>()))
     }
+
+
+    lateinit var nothing: Nothing
+    val nullableNothing: Nothing? = null
+
+    val nothingType =  ::nothing.returnType
+    val nullNothingType =  ::nullableNothing.returnType
+
+    @Test
+    fun testNothingSubtypes() {
+        println(nothingType)
+        println(nullNothingType)
+        assert(nothingType.isSubtypeOf(nullNothingType))
+        assert(!nullNothingType.isSubtypeOf(nothingType))
+    }
 }