use new hook to verify whether directive argument value is correct

Author: dariuszkuc

generator/graphql-kotlin-federation/src/main/kotlin/com/expediagroup/graphql/generator/federation/FederatedSchemaGeneratorHooks.kt

@@ -22,6 +22,7 @@ import com.expediagroup.graphql.generator.TopLevelObject
 import com.expediagroup.graphql.generator.annotations.GraphQLName
 import com.expediagroup.graphql.generator.directives.DirectiveMetaInformation
 import com.expediagroup.graphql.generator.federation.directives.COMPOSE_DIRECTIVE_NAME
+import com.expediagroup.graphql.generator.federation.directives.CONTACT_DIRECTIVE_NAME
 import com.expediagroup.graphql.generator.federation.directives.EXTENDS_DIRECTIVE_NAME
 import com.expediagroup.graphql.generator.federation.directives.EXTENDS_DIRECTIVE_TYPE
 import com.expediagroup.graphql.generator.federation.directives.EXTERNAL_DIRECTIVE_NAME
@@ -64,13 +65,11 @@ import com.expediagroup.graphql.generator.federation.types._Service
 import com.expediagroup.graphql.generator.federation.types.generateEntityFieldDefinition
 import com.expediagroup.graphql.generator.federation.validation.FederatedSchemaValidator
 import com.expediagroup.graphql.generator.hooks.SchemaGeneratorHooks
-import com.expediagroup.graphql.generator.internal.types.DEFAULT_DIRECTIVE_STRING_VALUE
 import graphql.TypeResolutionEnvironment
 import graphql.schema.DataFetcher
 import graphql.schema.FieldCoordinates
 import graphql.schema.GraphQLCodeRegistry
 import graphql.schema.GraphQLDirective
-import graphql.schema.GraphQLNamedOutputType
 import graphql.schema.GraphQLNamedType
 import graphql.schema.GraphQLObjectType
 import graphql.schema.GraphQLScalarType
@@ -150,15 +149,13 @@ open class FederatedSchemaGeneratorHooks(
             val appliedLinkDirectives = schemaObject?.kClass?.annotations?.filterIsInstance(LinkDirective::class.java)
             appliedLinkDirectives?.forEach { appliedDirectiveAnnotation ->
                 val specUrl = Paths.get(appliedDirectiveAnnotation.url)
-                // TODO verify supported version?
-                val specVersion = specUrl.fileName.name
                 val spec = specUrl.parent.fileName.name
 
                 if (linkSpecs.containsKey(spec)) {
                     throw RuntimeException("Attempting to import same @link spec twice")
                 } else {
                     val nameSpace: String = appliedDirectiveAnnotation.`as`.takeIf {
-                        it.isNotBlank() && it != DEFAULT_DIRECTIVE_STRING_VALUE
+                        it.isNotBlank()
                     } ?: spec
                     val imports: Map<String, String> = appliedDirectiveAnnotation.import.associate {
                         normalizeImportName(it.name) to normalizeImportName(it.`as`)
@@ -229,6 +226,16 @@ open class FederatedSchemaGeneratorHooks(
         else -> super.willGenerateDirective(directiveInfo)
     }
 
+    override fun isValidDirectiveArgumentValue(directiveName: String, argumentName: String, value: Any?): Boolean {
+        if (directiveName == LINK_DIRECTIVE_NAME && argumentName == "as" && value.toString().isBlank()) {
+            return false
+        }
+        if (directiveName == CONTACT_DIRECTIVE_NAME && (argumentName == "url" || argumentName == "description") && value.toString().isBlank()) {
+            return false
+        }
+        return super.isValidDirectiveArgumentValue(directiveName, argumentName, value)
+    }
+
     override fun didGenerateGraphQLType(type: KType, generatedType: GraphQLType): GraphQLType {
         validator.validateGraphQLType(generatedType)
         return super.didGenerateGraphQLType(type, generatedType)

generator/graphql-kotlin-federation/src/main/kotlin/com/expediagroup/graphql/generator/federation/directives/ContactDirective.kt

@@ -17,7 +17,6 @@
 package com.expediagroup.graphql.generator.federation.directives
 
 import com.expediagroup.graphql.generator.annotations.GraphQLDirective
-import com.expediagroup.graphql.generator.internal.types.DEFAULT_DIRECTIVE_STRING_VALUE
 import graphql.introspection.Introspection.DirectiveLocation
 
 /**
@@ -60,9 +59,9 @@ annotation class ContactDirective(
     /** Contact title of the subgraph owner */
     val name: String,
     /** URL where the subgraph's owner can be reached */
-    val url: String = DEFAULT_DIRECTIVE_STRING_VALUE,
+    val url: String = "",
     /** Other relevant notes can be included here; supports Markdown links */
-    val description: String = DEFAULT_DIRECTIVE_STRING_VALUE
+    val description: String = ""
 )
 
 internal const val CONTACT_DIRECTIVE_NAME = "contact"

generator/graphql-kotlin-federation/src/main/kotlin/com/expediagroup/graphql/generator/federation/directives/LinkDirective.kt

@@ -17,7 +17,6 @@
 package com.expediagroup.graphql.generator.federation.directives
 
 import com.expediagroup.graphql.generator.annotations.GraphQLDirective
-import com.expediagroup.graphql.generator.internal.types.DEFAULT_DIRECTIVE_STRING_VALUE
 import graphql.Scalars
 import graphql.introspection.Introspection.DirectiveLocation
 import graphql.schema.GraphQLArgument
@@ -59,7 +58,7 @@ const val FEDERATION_LATEST_VERSION = "2.5"
     description = LINK_DIRECTIVE_DESCRIPTION,
     locations = [DirectiveLocation.SCHEMA]
 )
-annotation class LinkDirective(val url: String, val `as`: String = DEFAULT_DIRECTIVE_STRING_VALUE, val import: Array<LinkImport>)
+annotation class LinkDirective(val url: String, val `as`: String = "", val import: Array<LinkImport>)
 
 internal const val LINK_DIRECTIVE_NAME = "link"
 private const val LINK_DIRECTIVE_DESCRIPTION = "Links definitions within the document to external schemas."

generator/graphql-kotlin-schema-generator/src/main/kotlin/com/expediagroup/graphql/generator/hooks/SchemaGeneratorHooks.kt

@@ -28,6 +28,8 @@ import com.expediagroup.graphql.generator.exceptions.EmptySubscriptionTypeExcept
 import com.expediagroup.graphql.generator.internal.extensions.isSubclassOf
 import com.expediagroup.graphql.generator.internal.extensions.isValidAdditionalType
 import graphql.schema.FieldCoordinates
+import graphql.schema.GraphQLAppliedDirective
+import graphql.schema.GraphQLArgument
 import graphql.schema.GraphQLCodeRegistry
 import graphql.schema.GraphQLDirective
 import graphql.schema.GraphQLFieldDefinition
@@ -39,6 +41,7 @@ import graphql.schema.GraphQLSchemaElement
 import graphql.schema.GraphQLType
 import graphql.schema.GraphQLTypeUtil
 import org.reactivestreams.Publisher
+import kotlin.reflect.KAnnotatedElement
 import kotlin.reflect.KClass
 import kotlin.reflect.KFunction
 import kotlin.reflect.KProperty
@@ -135,6 +138,11 @@ interface SchemaGeneratorHooks {
      */
     fun isValidAdditionalType(kClass: KClass<*>, inputType: Boolean): Boolean = kClass.isValidAdditionalType(inputType)
 
+    /**
+     * Called before setting applied directive argument value.
+     */
+    fun isValidDirectiveArgumentValue(directiveName: String, argumentName: String, value: Any?): Boolean = true
+
     /**
      * Called after `willGenerateGraphQLType` and before `didGenerateGraphQLType`.
      * Enables you to change the wiring, e.g. apply directives to alter the target type.

generator/graphql-kotlin-schema-generator/src/main/kotlin/com/expediagroup/graphql/generator/internal/types/generateDirective.kt

@@ -33,9 +33,6 @@ import kotlin.reflect.KProperty
 import kotlin.reflect.full.hasAnnotation
 import com.expediagroup.graphql.generator.annotations.GraphQLDirective as GraphQLDirectiveAnnotation
 
-const val DEFAULT_DIRECTIVE_STRING_VALUE = "DEFAULT_VALUE"
-const val DEFAULT_DIRECTIVE_INT_VALUE = Int.MIN_VALUE
-
 internal fun generateDirectives(
     generator: SchemaGenerator,
     element: KAnnotatedElement,
@@ -99,12 +96,10 @@ private fun getDirective(generator: SchemaGenerator, directiveInfo: DirectiveMet
         directive.toAppliedDirective()
             .transform { builder ->
                 directiveInfo.directive.annotationClass.getValidProperties(generator.config.hooks).forEach { prop ->
-                    // TODO how to handle/skip default values
                     val argumentToBeModified = directive.getArgument(prop.name)
                     if (argumentToBeModified != null) {
                         val value = prop.call(directiveInfo.directive)
-                        // annotations cannot have null values, we should skip known defaults
-                        if (value != DEFAULT_DIRECTIVE_STRING_VALUE && value != DEFAULT_DIRECTIVE_INT_VALUE) {
+                        if (generator.config.hooks.isValidDirectiveArgumentValue(directiveName, prop.name, value)) {
                             argumentToBeModified.toAppliedArgument()
                                 .transform { argumentBuilder ->
                                     argumentBuilder.valueProgrammatic(value)