[federation] use federation-jvm ServiceSDLPrinter (ExpediaGroup#1546)

Updated `FederatedSchemaGeneratorHooks` to use `ServiceSDLPrinter` provided by the `federation-jvm` in favor of our custom printer logic.

Author: dariuszkuc

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

@@ -16,10 +16,10 @@
 
 package com.expediagroup.graphql.generator.federation
 
+import com.apollographql.federation.graphqljava.printer.ServiceSDLPrinter.generateServiceSDL
+import com.apollographql.federation.graphqljava.printer.ServiceSDLPrinter.generateServiceSDLV2
 import com.expediagroup.graphql.generator.annotations.GraphQLName
-import com.expediagroup.graphql.generator.directives.DEPRECATED_DIRECTIVE_NAME
 import com.expediagroup.graphql.generator.directives.DirectiveMetaInformation
-import com.expediagroup.graphql.generator.extensions.print
 import com.expediagroup.graphql.generator.federation.directives.EXTENDS_DIRECTIVE_TYPE
 import com.expediagroup.graphql.generator.federation.directives.EXTERNAL_DIRECTIVE_TYPE
 import com.expediagroup.graphql.generator.federation.directives.FEDERATION_SPEC_URL
@@ -61,18 +61,13 @@ import graphql.schema.GraphQLDirective
 import graphql.schema.GraphQLObjectType
 import graphql.schema.GraphQLSchema
 import graphql.schema.GraphQLType
-import java.util.function.Predicate
 import kotlin.reflect.KType
 import kotlin.reflect.full.findAnnotation
 
 /**
  * Hooks for generating federated GraphQL schema.
  */
 open class FederatedSchemaGeneratorHooks(private val resolvers: List<FederatedTypeResolver<*>>, private val optInFederationV2: Boolean = false) : SchemaGeneratorHooks {
-    private val scalarDefinitionRegex = "(^\".+\"$[\\r\\n])?^scalar (_FieldSet|_Any)$[\\r\\n]*".toRegex(setOf(RegexOption.MULTILINE, RegexOption.IGNORE_CASE))
-    private val emptyQueryRegex = "^type Query @extends \\s*\\{\\s*}\\s*".toRegex(setOf(RegexOption.MULTILINE, RegexOption.IGNORE_CASE))
-    private val serviceFieldRegex = "\\s*_service: _Service!".toRegex(setOf(RegexOption.MULTILINE, RegexOption.IGNORE_CASE))
-    private val serviceTypeRegex = "^type _Service\\s*\\{\\s*sdl: String!\\s*}\\s*".toRegex(setOf(RegexOption.MULTILINE, RegexOption.IGNORE_CASE))
     private val validator = FederatedSchemaValidator()
 
     private val federationV2OnlyDirectiveNames: Set<String> = setOf(
@@ -206,17 +201,11 @@ open class FederatedSchemaGeneratorHooks(private val resolvers: List<FederatedTy
      * https://www.apollographql.com/docs/apollo-server/federation/federation-spec/#query_service
      */
     private fun getFederatedServiceSdl(schema: GraphQLSchema): String {
-        val directivesToInclude: List<String> = federatedDirectiveList().map { it.name }.plus(DEPRECATED_DIRECTIVE_NAME)
-        val customDirectivePredicate: Predicate<String> = Predicate { directivesToInclude.contains(it) }
-        return schema.print(
-            includeDefaultSchemaDefinition = optInFederationV2,
-            includeDirectiveDefinitions = false,
-            includeDirectivesFilter = customDirectivePredicate
-        ).replace(scalarDefinitionRegex, "")
-            .replace(serviceFieldRegex, "")
-            .replace(serviceTypeRegex, "")
-            .replace(emptyQueryRegex, "")
-            .trim()
+        return if (optInFederationV2) {
+            generateServiceSDLV2(schema)
+        } else {
+            generateServiceSDL(schema, false)
+        }
     }
 
     /**

generator/graphql-kotlin-federation/src/test/kotlin/com/expediagroup/graphql/generator/federation/execution/ServiceQueryResolverTest.kt

@@ -39,6 +39,10 @@ import kotlin.test.assertNotNull
 // SDL is returned without _entity and _service queries
 const val FEDERATED_SERVICE_SDL =
 """
+schema {
+  query: Query
+}
+
 interface Product @extends @key(fields : "id") @key(fields : "upc") {
   id: String! @external
   reviews: [Review!]!
@@ -54,6 +58,8 @@ type Book implements Product @extends @key(fields : "id") @key(fields : "upc") {
   weight: Float! @external
 }
 
+type Query @extends
+
 type Review {
   body: String!
   content: String @deprecated(reason : "no longer supported, replace with use Review.body instead")
@@ -75,6 +81,10 @@ scalar CustomScalar"""
 
 const val BASE_SERVICE_SDL =
 """
+schema {
+  query: Query
+}
+
 type Query @extends {
   getSimpleNestedObject: [SelfReferenceObject]!
   hello(name: String!): String!
@@ -93,6 +103,23 @@ schema @link(url : "https://specs.apollo.dev/link/v1.0/") @link(import : ["exten
   query: Query
 }
 
+directive @custom on SCHEMA | SCALAR | OBJECT | FIELD_DEFINITION | ARGUMENT_DEFINITION | INTERFACE | UNION | ENUM | ENUM_VALUE | INPUT_OBJECT | INPUT_FIELD_DEFINITION
+
+"Marks target object as extending part of the federated schema"
+directive @extends on OBJECT | INTERFACE
+
+"Marks target field as external meaning it will be resolved by federated schema"
+directive @external on FIELD_DEFINITION
+
+"Space separated list of primary keys needed to access federated object"
+directive @key(fields: _FieldSet!, resolvable: Boolean = true) repeatable on OBJECT | INTERFACE
+
+"Specifies the base type field set that will be selectable by the gateway"
+directive @provides(fields: _FieldSet!) on FIELD_DEFINITION
+
+"Specifies required input field set from the base type for a resolver"
+directive @requires(fields: _FieldSet!) on FIELD_DEFINITION
+
 interface Product @extends @key(fields : "id", resolvable : true) @key(fields : "upc", resolvable : true) {
   id: String! @external
   reviews: [Review!]!
@@ -112,8 +139,12 @@ type CustomScalar {
   value: String!
 }
 
+type Query @extends {
+  _service: _Service!
+}
+
 type Review {
-  body: String!
+  body: String! @custom
   content: String @deprecated(reason : "no longer supported, replace with use Review.body instead")
   customScalar: CustomScalar!
   id: String!
@@ -123,6 +154,13 @@ type User @extends @key(fields : "userId", resolvable : true) {
   name: String! @external
   userId: Int! @external
 }
+
+type _Service {
+  sdl: String!
+}
+
+"Federation type representing set of fields"
+scalar _FieldSet
 """
 
 class ServiceQueryResolverTest {

gradle.properties

@@ -22,8 +22,8 @@ kotlinxSerializationVersion = 1.3.2
 
 androidPluginVersion = 7.1.2
 classGraphVersion = 4.8.149
-federationGraphQLVersion = 2.0.4
-graphQLJavaVersion = 19.1
+federationGraphQLVersion = 2.0.7
+graphQLJavaVersion = 19.2
 graphQLJavaDataLoaderVersion = 3.2.0
 jacksonVersion = 2.13.3
 # KotlinPoet v1.12.0+ requires Kotlin v1.7