fix: workaround to SpringBoot GraalVM issue

SpringBoot is currently unable to register nested enum configuration classes. Looks like previous versions (<3.1.3) were not detecting this. Moving enum classes to a top level class fixes the issue.

Author: dariuszkuc

servers/graphql-kotlin-spring-server/src/main/kotlin/com/expediagroup/graphql/server/spring/GraphQLConfigurationProperties.kt

@@ -98,11 +98,6 @@ data class GraphQLConfigurationProperties(
         val protocol: SubscriptionProtocol = SubscriptionProtocol.GRAPHQL_WS
     )
 
-    enum class SubscriptionProtocol {
-        APOLLO_SUBSCRIPTIONS_WS,
-        GRAPHQL_WS
-    }
-
     /**
      * Playground configuration properties.
      */
@@ -141,11 +136,6 @@ data class GraphQLConfigurationProperties(
         val enabled: Boolean = true
     )
 
-    /**
-     * Approaches for batching transactions of a set of GraphQL Operations.
-     */
-    enum class BatchingStrategy { LEVEL_DISPATCHED, SYNC_EXHAUSTION }
-
     /**
      * Batching configuration properties.
      */
@@ -161,3 +151,19 @@ data class GraphQLConfigurationProperties(
         val enabled: Boolean = false
     )
 }
+
+// workaround to Spring GraalVM native issue
+// when using nested configuration enum classes Spring Boot is unable to bind them correctly
+
+enum class SubscriptionProtocol {
+    APOLLO_SUBSCRIPTIONS_WS,
+    GRAPHQL_WS
+}
+
+/**
+ * Approaches for batching transactions of a set of GraphQL Operations.
+ */
+enum class BatchingStrategy {
+    LEVEL_DISPATCHED,
+    SYNC_EXHAUSTION
+}

servers/graphql-kotlin-spring-server/src/main/kotlin/com/expediagroup/graphql/server/spring/GraphQLSchemaConfiguration.kt

@@ -91,8 +91,8 @@ class GraphQLSchemaConfiguration {
                     builder.doNotAddDefaultInstrumentations()
                     instrumentations.add(
                         when (config.batching.strategy) {
-                            GraphQLConfigurationProperties.BatchingStrategy.LEVEL_DISPATCHED -> DataLoaderLevelDispatchedInstrumentation()
-                            GraphQLConfigurationProperties.BatchingStrategy.SYNC_EXHAUSTION -> DataLoaderSyncExecutionExhaustedInstrumentation()
+                            BatchingStrategy.LEVEL_DISPATCHED -> DataLoaderLevelDispatchedInstrumentation()
+                            BatchingStrategy.SYNC_EXHAUSTION -> DataLoaderSyncExecutionExhaustedInstrumentation()
                         }
                     )
                 }