fix #79 enum toJson serialization

lynglib/src/commonMain/kotlin/net/sergeych/lyng/obj/ObjEnum.kt

@@ -15,6 +15,8 @@
  *
  */
 
+import kotlinx.serialization.json.JsonElement
+import kotlinx.serialization.json.JsonPrimitive
 import net.sergeych.lyng.Scope
 import net.sergeych.lyng.obj.*
 import net.sergeych.lynon.LynonDecoder
@@ -38,6 +40,10 @@ open class ObjEnumEntry(enumClass: ObjEnumClass, val name: ObjString, val ordina
         return ordinal.compareTo(scope, other.ordinal)
     }
 
+    override suspend fun toJson(scope: Scope): JsonElement {
+        return JsonPrimitive(name.value)
+    }
+
 }
 
 object EnumBase : ObjClass("Enum") {

lynglib/src/commonTest/kotlin/ScriptTest.kt

@@ -3997,17 +3997,19 @@ class ScriptTest {
     }
 
     @Serializable
-    data class TestEnum(
-        val value: Int,
-        val inner: JsonObject
-    )
+    enum class TestEnum {
+        One, Two
+    }
+    @Serializable
+    data class TestJson4(val value: TestEnum)
+
     @Test
     fun deserializeEnumJsonTest() = runTest {
         val x = eval("""
             import lyng.serialization
-            enum 
-            { value: 12, inner: { "foo": 1, "bar": "two" }}
-        """.trimIndent()).decodeSerializable<TestJson3>()
-        assertEquals(TestJson3(12, JsonObject(mapOf("foo" to JsonPrimitive(1), "bar" to Json.encodeToJsonElement("two")))), x)
+            enum TestEnum { One, Two }
+            { value: TestEnum.One }
+        """.trimIndent()).decodeSerializable<TestJson4>()
+        assertEquals( TestJson4(TestEnum.One), x)
     }
 }