Add proper virtual type definition

lib/src/main/java/graphql/nadel/definition/virtualType/NadelVirtualTypeDefinition.kt

@@ -0,0 +1,26 @@
+package graphql.nadel.definition.virtualType
+
+import graphql.language.DirectiveDefinition
+import graphql.nadel.engine.util.parseDefinition
+import graphql.schema.GraphQLDirectiveContainer
+import graphql.schema.GraphQLSchemaElement
+
+internal fun GraphQLSchemaElement.isVirtualType(): Boolean {
+    return (this as? GraphQLDirectiveContainer)
+        ?.hasAppliedDirective(NadelVirtualTypeDefinition.directiveDefinition.name) == true
+}
+
+internal class NadelVirtualTypeDefinition {
+    companion object {
+        val directiveDefinition = parseDefinition<DirectiveDefinition>(
+            // language=GraphQL
+            """
+              directive @virtualType on OBJECT
+            """.trimIndent(),
+        )
+    }
+
+    object Keyword {
+        const val virtualType = "virtualType"
+    }
+}

lib/src/main/java/graphql/nadel/engine/util/GraphQLUtil.kt

@@ -69,6 +69,7 @@ import graphql.schema.GraphQLUnionType
 import graphql.schema.GraphQLUnmodifiedType
 import graphql.schema.idl.TypeUtil
 import kotlinx.coroutines.future.asDeferred
+import org.intellij.lang.annotations.Language
 
 internal typealias AnyAstValue = Value<*>
 internal typealias AnyAstNode = Node<*>
@@ -649,6 +650,9 @@ internal fun ExecutableNormalizedField.getFieldDefinitionSequence(
         }
 }
 
-internal inline fun <reified T : SDLDefinition<*>> parseDefinition(sdl: String): T {
+internal inline fun <reified T : SDLDefinition<*>> parseDefinition(
+    @Language("GraphQL")
+    sdl: String,
+): T {
     return Parser.parse(sdl).definitions.singleOfType()
 }

lib/src/main/java/graphql/nadel/schema/NadelDirectives.kt

@@ -10,6 +10,7 @@ import graphql.nadel.definition.hydration.NadelHydrationResultConditionDefinitio
 import graphql.nadel.definition.hydration.NadelHydrationResultFieldPredicateDefinition
 import graphql.nadel.definition.partition.NadelPartitionDefinition
 import graphql.nadel.definition.renamed.NadelRenamedDefinition
+import graphql.nadel.definition.virtualType.NadelVirtualTypeDefinition
 import graphql.nadel.engine.util.singleOfType
 import graphql.parser.Parser
 
@@ -71,6 +72,8 @@ object NadelDirectives {
 
     val partitionDirectiveDefinition = NadelPartitionDefinition.directiveDefinition
 
+    val virtualTypeDirectiveDefinition = NadelVirtualTypeDefinition.directiveDefinition
+
     private inline fun <reified T : SDLDefinition<*>> parseDefinition(sdl: String): T {
         return Parser.parse(sdl).definitions.singleOfType()
     }

lib/src/main/java/graphql/nadel/schema/OverallSchemaGenerator.kt

@@ -63,6 +63,7 @@ internal class OverallSchemaGenerator {
         // add our custom directives if they are not present
         addIfNotPresent(overallRegistry, allDefinitions, NadelDirectives.nadelHydrationArgumentDefinition)
         addIfNotPresent(overallRegistry, allDefinitions, NadelDirectives.hydratedDirectiveDefinition)
+        addIfNotPresent(overallRegistry, allDefinitions, NadelDirectives.virtualTypeDirectiveDefinition)
         addIfNotPresent(overallRegistry, allDefinitions, NadelDirectives.renamedDirectiveDefinition)
         addIfNotPresent(overallRegistry, allDefinitions, NadelDirectives.hiddenDirectiveDefinition)
         addIfNotPresent(overallRegistry, allDefinitions, NadelDirectives.nadelBatchObjectIdentifiedByDefinition)

lib/src/main/java/graphql/nadel/validation/util/NadelBuiltInTypes.kt

@@ -10,15 +10,16 @@ import graphql.nadel.schema.NadelDirectives.deferDirectiveDefinition
 import graphql.nadel.schema.NadelDirectives.dynamicServiceDirectiveDefinition
 import graphql.nadel.schema.NadelDirectives.hiddenDirectiveDefinition
 import graphql.nadel.schema.NadelDirectives.hydratedDirectiveDefinition
-import graphql.nadel.schema.NadelDirectives.nadelHydrationRemainingArguments
 import graphql.nadel.schema.NadelDirectives.nadelBatchObjectIdentifiedByDefinition
 import graphql.nadel.schema.NadelDirectives.nadelHydrationArgumentDefinition
 import graphql.nadel.schema.NadelDirectives.nadelHydrationConditionDefinition
+import graphql.nadel.schema.NadelDirectives.nadelHydrationRemainingArguments
 import graphql.nadel.schema.NadelDirectives.nadelHydrationResultConditionDefinition
 import graphql.nadel.schema.NadelDirectives.nadelHydrationResultFieldPredicateDefinition
 import graphql.nadel.schema.NadelDirectives.namespacedDirectiveDefinition
 import graphql.nadel.schema.NadelDirectives.partitionDirectiveDefinition
 import graphql.nadel.schema.NadelDirectives.renamedDirectiveDefinition
+import graphql.nadel.schema.NadelDirectives.virtualTypeDirectiveDefinition
 
 object NadelBuiltInTypes {
     val builtInScalars = setOf(
@@ -50,6 +51,8 @@ object NadelBuiltInTypes {
         nadelHydrationResultConditionDefinition,
         nadelHydrationConditionDefinition,
         nadelHydrationRemainingArguments,
+
+        virtualTypeDirectiveDefinition,
     ).mapTo(LinkedHashSet()) {
         it.name
     }

test/src/test/kotlin/graphql/nadel/tests/next/fixtures/hydration/copy/HydrationCopiesFieldAndHasPolymorphicHydrationTest.kt

@@ -228,7 +228,6 @@ class HydrationCopiesFieldAndHasPolymorphicHydrationTest : NadelIntegrationTest(
                       ]
                     )
                 }
-                directive @virtualType on OBJECT
                 type WorkConnection @virtualType {
                   edges: [WorkEdge]
                   pageInfo: PageInfo

test/src/test/kotlin/graphql/nadel/tests/next/fixtures/hydration/copy/HydrationCopiesFieldHintOffTest.kt

@@ -168,7 +168,6 @@ class HydrationCopiesFieldHintOffTest : NadelIntegrationTest(
                       ]
                     )
                 }
-                directive @virtualType on OBJECT
                 type WorkConnection @virtualType {
                   edges: [WorkEdge]
                   pageInfo: PageInfo

test/src/test/kotlin/graphql/nadel/tests/next/fixtures/hydration/copy/HydrationCopiesFieldTest.kt

@@ -168,7 +168,6 @@ class HydrationCopiesFieldTest : NadelIntegrationTest(
                       ]
                     )
                 }
-                directive @virtualType on OBJECT
                 type WorkConnection @virtualType {
                   edges: [WorkEdge]
                   pageInfo: PageInfo