Add federation 2.8, fix federation v2 introspection (#2273)

core/src/main/scala/caliban/Value.scala

@@ -9,6 +9,7 @@ import caliban.interop.zio.{ IsZIOJsonDecoder, IsZIOJsonEncoder }
 import caliban.rendering.ValueRenderer
 import zio.stream.Stream
 
+import scala.annotation.tailrec
 import scala.util.control.NonFatal
 import scala.util.hashing.MurmurHash3
 
@@ -67,6 +68,38 @@ sealed trait ResponseValue extends Serializable { self =>
   }
 }
 object ResponseValue {
+
+  def at(path: List[PathValue])(value: ResponseValue): ResponseValue = {
+    def loop(path: List[PathValue], value: ResponseValue): ResponseValue = path match {
+      case Nil                            => value
+      case PathValue.Key(key) :: tail     =>
+        value match {
+          case ObjectValue(fields) =>
+            fields.find(_._1 == key) match {
+              case Some((_, v)) => loop(tail, v)
+              case None         => Value.NullValue
+            }
+          case ListValue(values)   =>
+            ListValue(values.map(loop(path, _)))
+          case _                   => Value.NullValue
+        }
+      case PathValue.Index(index) :: tail =>
+        value match {
+          case ListValue(values) =>
+            val idx = index
+            if (idx < values.size) {
+              loop(tail, values(idx))
+            } else {
+              Value.NullValue
+            }
+          case _                 => Value.NullValue
+        }
+      case _                              => Value.NullValue
+    }
+
+    loop(path, value)
+  }
+
   case class ListValue(values: List[ResponseValue])                extends ResponseValue {
     override def toString: String = ValueRenderer.responseListValueRenderer.renderCompact(this)
   }

examples/src/main/resources/gateway_v2/package.json

@@ -10,8 +10,8 @@
   "keywords": [],
   "license": "MIT",
   "dependencies": {
-    "@apollo/server": "4.9.5",
-    "@apollo/gateway": "2.6.2",
+    "@apollo/gateway": "2.8.0",
+    "@apollo/server": "4.10.4",
     "graphql": "16.8.1"
   }
 }

federation/src/main/scala/caliban/federation/FederationSupport.scala

@@ -13,24 +13,29 @@ abstract class FederationSupport(
 ) {
   import FederationHelpers._
 
+  // This is a bit of a hack to determine if we are using the v1 version of the federation spec
+  // All of the v2 directives come through schema directives while the v1 is through the supported directives field instead
+  private val isV1       = supportedDirectives.nonEmpty && schemaDirectives.isEmpty
+  private val extraTypes = if (isV1) List(fieldSetSchema.toType_()) else Nil
+
   /**
    * Accepts a GraphQL and returns a GraphQL with the minimum settings to support federation. This variant does not
    * provide any stitching capabilities, it merely makes this schema consumable by a graphql federation gateway.
    * @param original The original schema
    * @return A new schema which has been augmented with federation types
    */
   def federate[R](original: GraphQL[R]): GraphQL[R] = {
-    import caliban.schema.Schema.auto._
-
     case class Query(
-      _service: _Service,
-      _fieldSet: FieldSet = FieldSet("")
+      _service: _Service
     )
 
+    implicit val serviceSchema = Schema.gen[R, _Service]
+    implicit val querySchema   = Schema.gen[R, Query]
+
     graphQL(
       RootResolver(Query(_service = _Service(original.withSchemaDirectives(schemaDirectives).render))),
       supportedDirectives
-    ) |+| original
+    ).withAdditionalTypes(extraTypes) |+| original
   }
 
   def federated[R](resolver: EntityResolver[R], others: EntityResolver[R]*): GraphQLAspect[Nothing, R] =
@@ -57,7 +62,6 @@ abstract class FederationSupport(
     val resolvers = resolver +: otherResolvers.toList
 
     val genericSchema = new GenericSchema[R] {}
-    import genericSchema.auto._
 
     implicit val entitySchema: Schema[R, _Entity] = new Schema[R, _Entity] {
       override def nullable: Boolean                                         = true
@@ -84,14 +88,17 @@ abstract class FederationSupport(
 
     case class Query(
       _entities: RepresentationsArgs => List[_Entity],
-      _service: ZQuery[Any, Nothing, _Service],
-      _fieldSet: FieldSet = FieldSet("")
+      _service: ZQuery[Any, Nothing, _Service]
     )
 
     val withSDL = original
       .withAdditionalTypes(resolvers.map(_.toType).flatMap(Types.collectTypes(_)))
       .withSchemaDirectives(schemaDirectives)
 
+    implicit val representationsArgsSchema: Schema[Any, RepresentationsArgs] = Schema.gen
+    implicit val serviceSchema: Schema[R, _Service]                          = genericSchema.gen[R, _Service]
+    implicit val querySchema: Schema[R, Query]                               = genericSchema.gen[R, Query]
+
     graphQL[R, Query, Unit, Unit](
       RootResolver(
         Query(
@@ -100,7 +107,7 @@ abstract class FederationSupport(
         )
       ),
       supportedDirectives
-    ) |+| original
+    ).withAdditionalTypes(extraTypes) |+| original
 
   }
 }

federation/src/main/scala/caliban/federation/package.scala

@@ -4,6 +4,7 @@ import caliban.federation.v2x.{
   FederationDirectivesV2_3,
   FederationDirectivesV2_5,
   FederationDirectivesV2_6,
+  FederationDirectivesV2_8,
   FederationV2,
   Versions
 }
@@ -17,5 +18,7 @@ package object federation {
   lazy val v2_4 = new FederationV2(List(Versions.v2_4)) with FederationDirectivesV2_3
   lazy val v2_5 = new FederationV2(List(Versions.v2_5)) with FederationDirectivesV2_5
   lazy val v2_6 = new FederationV2(List(Versions.v2_6)) with FederationDirectivesV2_6
+  lazy val v2_7 = new FederationV2(List(Versions.v2_7)) with FederationDirectivesV2_6
+  lazy val v2_8 = new FederationV2(List(Versions.v2_8)) with FederationDirectivesV2_8
 
 }

federation/src/main/scala/caliban/federation/v2x/FederationDirectivesV2_8.scala

@@ -0,0 +1,16 @@
+package caliban.federation.v2x
+
+import caliban.Value.StringValue
+import caliban.parsing.adt.Directive
+import caliban.schema.Annotations.GQLDirective
+
+trait FederationDirectivesV2_8 extends FederationDirectivesV2_6 {
+
+  def Context(context: String) = Directive("context", Map("context" -> StringValue(context)))
+
+  case class GQLContext(context: String) extends GQLDirective(Context(context))
+
+  def FromContext(context: String) = Directive("fromContext", Map("context" -> StringValue(context)))
+
+  case class GQLFromContext(context: String) extends GQLDirective(FromContext(context))
+}

federation/src/main/scala/caliban/federation/v2x/FederationV2.scala

@@ -52,4 +52,14 @@ object FederationV2 {
     `import` = v2_5.`import` :+ Import("@policy")
   )
 
+  private[v2x] val v2_7 = Link(
+    url = s"$federationV2Url/v2.7",
+    `import` = v2_6.`import`
+  )
+
+  private[v2x] val v2_8 = Link(
+    url = s"$federationV2Url/v2.8",
+    `import` = v2_7.`import` :+ Import("@context") :+ Import("@fromContext")
+  )
+
 }

federation/src/main/scala/caliban/federation/v2x/Versions.scala

@@ -8,5 +8,7 @@ object Versions {
   val v2_4 = FederationV2.v2_4
   val v2_5 = FederationV2.v2_5
   val v2_6 = FederationV2.v2_6
+  val v2_7 = FederationV2.v2_7
+  val v2_8 = FederationV2.v2_8
 
 }

federation/src/test/scala/caliban/federation/FederationV1Spec.scala

@@ -150,6 +150,30 @@ object FederationV1Spec extends ZIOSpecDefault {
           )
         )
       }
+    },
+    test("introspection should include _Any and _FieldSet scalars") {
+      val interpreter = (graphQL(resolver) @@ federated(entityResolver)).interpreter
+
+      val query = gqldoc("""{ __schema { types { name } } }""")
+      interpreter
+        .flatMap(_.execute(query))
+        .map(d =>
+          ResponseValue.at(
+            PathValue.Key("__schema") :: PathValue.Key("types") :: PathValue.Key("name") :: Nil
+          )(d.data)
+        )
+        .map(responseValue =>
+          assertTrue(
+            responseValue
+              .is(_.subtype[ListValue])
+              .values
+              .contains(StringValue("_Any")),
+            responseValue
+              .is(_.subtype[ListValue])
+              .values
+              .contains(StringValue("_FieldSet"))
+          )
+        )
     }
   )
 }

federation/src/test/scala/caliban/federation/v2x/FederationV2Spec.scala

@@ -2,6 +2,7 @@ package caliban.federation.v2x
 
 import caliban.InputValue.{ ListValue, ObjectValue }
 import caliban.Macros.gqldoc
+import caliban.TestUtils._
 import caliban.Value.StringValue
 import caliban.parsing.Parser
 import caliban.parsing.adt.{ Definition, Directive }
@@ -11,7 +12,6 @@ import io.circe.Json
 import io.circe.parser.decode
 import zio.ZIO
 import zio.test.Assertion.{ hasSameElements, isSome }
-import zio.test.{ assertTrue, ZIOSpecDefault }
 import zio.test._
 
 object FederationV2Spec extends ZIOSpecDefault {
@@ -182,6 +182,30 @@ object FederationV2Spec extends ZIOSpecDefault {
             )
           )
         }
+      },
+      test("introspection doesn't contain _FieldSet scalar") {
+        import caliban.federation.v2_8._
+        val interpreter = (graphQL(resolver) @@ federated).interpreter
+        val query       = gqldoc("""{ __schema { types { name } } }""")
+        interpreter
+          .flatMap(_.execute(query))
+          .map(d =>
+            ResponseValue.at(
+              PathValue.Key("__schema") :: PathValue.Key("types") :: PathValue.Key("name") :: Nil
+            )(d.data)
+          )
+          .map(responseValue =>
+            assertTrue(
+              !responseValue
+                .is(_.subtype[ResponseValue.ListValue])
+                .values
+                .contains(StringValue("_Any")),
+              !responseValue
+                .is(_.subtype[ResponseValue.ListValue])
+                .values
+                .contains(StringValue("_FieldSet"))
+            )
+          )
       }
     )