Add support for interface implementing interface

modules/ast/src/main/scala/sangria/ast/QueryAst.scala

@@ -534,7 +534,8 @@ case class InterfaceTypeDefinition(
     description: Option[StringValue] = None,
     comments: Vector[Comment] = Vector.empty,
     trailingComments: Vector[Comment] = Vector.empty,
-    location: Option[AstLocation] = None)
+    location: Option[AstLocation] = None,
+    interfaces: Vector[NamedType] = Vector.empty)
     extends TypeDefinition
     with WithTrailingComments
     with WithDescription {
@@ -622,7 +623,8 @@ case class InterfaceTypeExtensionDefinition(
     directives: Vector[Directive] = Vector.empty,
     comments: Vector[Comment] = Vector.empty,
     trailingComments: Vector[Comment] = Vector.empty,
-    location: Option[AstLocation] = None)
+    location: Option[AstLocation] = None,
+    interfaces: Vector[NamedType] = Vector.empty)
     extends ObjectLikeTypeExtensionDefinition
     with WithTrailingComments {
   def rename(newName: String): InterfaceTypeExtensionDefinition = copy(name = newName)

modules/core/src/main/scala-2/sangria/macros/AstLiftable.scala

@@ -80,8 +80,8 @@ trait AstLiftable {
 
     case ObjectTypeExtensionDefinition(n, i, f, d, c, tc, p) =>
       q"_root_.sangria.ast.ObjectTypeExtensionDefinition($n, $i, $f, $d, $c, $tc, $p)"
-    case InterfaceTypeExtensionDefinition(n, f, d, c, tc, p) =>
-      q"_root_.sangria.ast.InterfaceTypeExtensionDefinition($n, $f, $d, $c, $tc, $p)"
+    case InterfaceTypeExtensionDefinition(n, f, d, c, tc, p, i) =>
+      q"_root_.sangria.ast.InterfaceTypeExtensionDefinition($n, $f, $d, $c, $tc, $p, $i)"
     case InputObjectTypeExtensionDefinition(n, f, d, c, tc, p) =>
       q"_root_.sangria.ast.InputObjectTypeExtensionDefinition($n, $f, $d, $c, $tc, $p)"
     case UnionTypeExtensionDefinition(n, t, d, c, p) =>
@@ -97,8 +97,8 @@ trait AstLiftable {
       q"_root_.sangria.ast.EnumTypeDefinition($n, $v, $d, $desc, $c, $tc, $p)"
     case InputObjectTypeDefinition(n, f, d, desc, c, tc, p) =>
       q"_root_.sangria.ast.InputObjectTypeDefinition($n, $f, $d, $desc, $c, $tc, $p)"
-    case InterfaceTypeDefinition(n, f, d, desc, c, tc, p) =>
-      q"_root_.sangria.ast.InterfaceTypeDefinition($n, $f, $d, $desc, $c, $tc, $p)"
+    case InterfaceTypeDefinition(n, f, d, desc, c, tc, p, i) =>
+      q"_root_.sangria.ast.InterfaceTypeDefinition($n, $f, $d, $desc, $c, $tc, $p, $i)"
     case ObjectTypeDefinition(n, i, f, d, desc, c, tc, p) =>
       q"_root_.sangria.ast.ObjectTypeDefinition($n, $i, $f, $d, $desc, $c, $tc, $p)"
     case ScalarTypeDefinition(n, d, desc, c, p) =>

modules/core/src/main/scala/sangria/ast/AstVisitor.scala

@@ -310,8 +310,10 @@ object AstVisitor {
               description,
               comment,
               trailingComments,
-              _) =>
+              _,
+              interfaces) =>
           if (breakOrSkip(onEnter(n))) {
+            interfaces.foreach(d => loop(d))
             fields.foreach(d => loop(d))
             dirs.foreach(d => loop(d))
             description.foreach(s => loop(s))
@@ -360,8 +362,9 @@ object AstVisitor {
             tc.foreach(s => loop(s))
             breakOrSkip(onLeave(n))
           }
-        case n @ InterfaceTypeExtensionDefinition(_, fields, dirs, comment, tc, _) =>
+        case n @ InterfaceTypeExtensionDefinition(_, fields, dirs, comment, tc, _, ints) =>
           if (breakOrSkip(onEnter(n))) {
+            ints.foreach(d => loop(d))
             fields.foreach(d => loop(d))
             dirs.foreach(d => loop(d))
             comment.foreach(s => loop(s))

modules/core/src/main/scala/sangria/introspection/IntrospectionParser.scala

@@ -65,7 +65,11 @@ object IntrospectionParser {
       possibleTypes = mapFieldOpt(tpe, "possibleTypes")
         .map(um.getListValue)
         .getOrElse(Vector.empty)
-        .map(i => parseNamedTypeRef(i, path :+ "possibleTypes"))
+        .map(i => parseNamedTypeRef(i, path :+ "possibleTypes")),
+      interfaces = mapFieldOpt(tpe, "interfaces")
+        .map(um.getListValue)
+        .getOrElse(Vector.empty)
+        .map(i => parseNamedTypeRef(i, path :+ "interfaces"))
     )
 
   private def parseUnion[In: InputUnmarshaller](tpe: In, path: Vector[String]) =

modules/core/src/main/scala/sangria/introspection/model.scala

@@ -61,7 +61,8 @@ case class IntrospectionInterfaceType(
     name: String,
     description: Option[String],
     fields: Seq[IntrospectionField],
-    possibleTypes: Seq[IntrospectionNamedTypeRef])
+    possibleTypes: Seq[IntrospectionNamedTypeRef],
+    interfaces: Seq[IntrospectionNamedTypeRef])
     extends IntrospectionType {
   val kind = TypeKind.Interface
 }

modules/core/src/main/scala/sangria/introspection/package.scala

@@ -274,8 +274,8 @@ package object introspection {
           resolve = _.value._2 match {
             case t: ObjectType[_, _] =>
               Some(t.allInterfaces.asInstanceOf[Vector[Type]].map(true -> _))
-            case _: InterfaceType[_, _] =>
-              Some(Vector.empty)
+            case t: InterfaceType[_, _] =>
+              Some(t.interfaces.asInstanceOf[List[Type]].map(true -> _))
             case _ => None
           }
         ),

modules/core/src/main/scala/sangria/renderer/QueryRenderer.scala

@@ -668,12 +668,16 @@ object QueryRenderer {
           renderDirs(dirs, config, indent, frontSep = true) +
           renderInputFieldDefinitions(fields, itd, indent, config, frontSep = true)
 
-      case itd @ InterfaceTypeDefinition(name, fields, dirs, description, _, _, _) =>
+      case itd @ InterfaceTypeDefinition(name, fields, dirs, description, _, _, _, interfaces) =>
         renderDescription(itd, prev, indent, config) +
           renderComment(itd, description.orElse(prev), indent, config) +
           indent.str + "interface" + config.mandatorySeparator + name +
-          renderDirs(dirs, config, indent, frontSep = true) +
-          renderFieldDefinitions(fields, itd, indent, config, frontSep = true)
+          (if (interfaces.nonEmpty) config.mandatorySeparator else "") +
+          renderInterfaces(interfaces, config, indent, withSep = false) +
+          (if (dirs.nonEmpty) config.separator else "") +
+          renderDirs(dirs, config, indent, withSep = false) +
+          (if (fields.nonEmpty) config.separator else "") +
+          renderFieldDefinitions(fields, itd, indent, config)
 
       case utd @ UnionTypeDefinition(name, types, dirs, description, _, _) =>
         val typesString =
@@ -728,11 +732,15 @@ object QueryRenderer {
           renderDirs(dirs, config, indent, withSep = fields.nonEmpty) +
           renderFieldDefinitions(fields, ted, indent, config)
 
-      case ext @ InterfaceTypeExtensionDefinition(name, fields, dirs, _, _, _) =>
+      case ext @ InterfaceTypeExtensionDefinition(name, fields, dirs, _, _, _, interfaces) =>
         renderComment(ext, prev, indent, config) +
           indent.str + "extend" + config.mandatorySeparator + "interface" + config.mandatorySeparator + name +
-          renderDirs(dirs, config, indent, frontSep = true) +
-          renderFieldDefinitions(fields, ext, indent, config, frontSep = true)
+          (if (interfaces.nonEmpty) config.mandatorySeparator else "") +
+          renderInterfaces(interfaces, config, indent, withSep = false) +
+          (if (dirs.nonEmpty) config.separator else "") +
+          renderDirs(dirs, config, indent, withSep = false) +
+          (if (fields.nonEmpty) config.separator else "") +
+          renderFieldDefinitions(fields, ext, indent, config)
 
       case ext @ UnionTypeExtensionDefinition(name, types, dirs, _, _) =>
         val typesString =

modules/core/src/main/scala/sangria/renderer/SchemaRenderer.scala

@@ -45,6 +45,9 @@ object SchemaRenderer {
   def renderImplementedInterfaces(tpe: IntrospectionObjectType) =
     tpe.interfaces.map(t => ast.NamedType(t.name)).toVector
 
+  def renderImplementedInterfaces(tpe: IntrospectionInterfaceType) =
+    tpe.interfaces.map(t => ast.NamedType(t.name)).toVector
+
   def renderImplementedInterfaces(tpe: ObjectLikeType[_, _]) =
     tpe.allInterfaces.map(t => ast.NamedType(t.name))
 
@@ -217,14 +220,16 @@ object SchemaRenderer {
     ast.InterfaceTypeDefinition(
       tpe.name,
       renderFieldsI(tpe.fields),
-      description = renderDescription(tpe.description))
+      description = renderDescription(tpe.description),
+      interfaces = renderImplementedInterfaces(tpe))
 
   def renderInterface(tpe: InterfaceType[_, _]) =
     ast.InterfaceTypeDefinition(
       tpe.name,
       renderFields(tpe.uniqueFields),
       tpe.astDirectives,
-      renderDescription(tpe.description))
+      renderDescription(tpe.description),
+      interfaces = renderImplementedInterfaces(tpe))
 
   def renderUnion(tpe: IntrospectionUnionType) =
     ast.UnionTypeDefinition(

modules/core/src/main/scala/sangria/schema/AstSchemaBuilder.scala

@@ -65,6 +65,15 @@ trait AstSchemaBuilder[Ctx] {
       fields: () => List[InputField[_]],
       mat: AstSchemaMaterializer[Ctx]): InputObjectType[T]
 
+  def buildInterfaceType(
+      origin: MatOrigin,
+      definition: ast.InterfaceTypeDefinition,
+      extensions: List[ast.InterfaceTypeExtensionDefinition],
+      fields: () => List[Field[Ctx, Any]],
+      interfaces: List[InterfaceType[Ctx, Any]],
+      mat: AstSchemaMaterializer[Ctx]): Option[InterfaceType[Ctx, Any]]
+
+  @deprecated
   def buildInterfaceType(
       origin: MatOrigin,
       definition: ast.InterfaceTypeDefinition,
@@ -439,6 +448,15 @@ class DefaultAstSchemaBuilder[Ctx] extends AstSchemaBuilder[Ctx] {
       definition: ast.InterfaceTypeDefinition,
       extensions: List[ast.InterfaceTypeExtensionDefinition],
       fields: () => List[Field[Ctx, Any]],
+      mat: AstSchemaMaterializer[Ctx]): Option[InterfaceType[Ctx, Any]] =
+    buildInterfaceType(origin, definition, extensions, fields, List.empty, mat)
+
+  def buildInterfaceType(
+      origin: MatOrigin,
+      definition: ast.InterfaceTypeDefinition,
+      extensions: List[ast.InterfaceTypeExtensionDefinition],
+      fields: () => List[Field[Ctx, Any]],
+      interfaces: List[InterfaceType[Ctx, Any]],
       mat: AstSchemaMaterializer[Ctx]): Option[InterfaceType[Ctx, Any]] = {
     val directives = definition.directives ++ extensions.flatMap(_.directives)
 
@@ -447,7 +465,7 @@ class DefaultAstSchemaBuilder[Ctx] extends AstSchemaBuilder[Ctx] {
         name = typeName(definition),
         description = typeDescription(definition),
         fieldsFn = fields,
-        interfaces = Nil,
+        interfaces = interfaces,
         manualPossibleTypes = () => Nil,
         astDirectives = directives,
         astNodes = (definition +: extensions).toVector

modules/core/src/main/scala/sangria/schema/AstSchemaMaterializer.scala

@@ -692,11 +692,13 @@ class AstSchemaMaterializer[Ctx] private (
       tpe: ast.InterfaceTypeDefinition): Option[InterfaceType[Ctx, Any]] = {
     val extensions = findInterfaceExtensions(tpe.name)
 
+    // TODO generate interfaces
     builder.buildInterfaceType(
       origin,
       tpe,
       extensions.toList,
       () => buildFields(origin, tpe, tpe.fields, extensions).toList,
+      extendInterfaces(origin, tpe, extensions),
       this)
   }
 
@@ -765,6 +767,18 @@ class AstSchemaMaterializer[Ctx] private (
     (ei ++ oi).toList
   }
 
+  def extendInterfaces(
+      origin: MatOrigin,
+      tpe: ast.InterfaceTypeDefinition,
+      extensions: Vector[ast.InterfaceTypeExtensionDefinition]): List[InterfaceType[Ctx, Any]] = {
+    val extraInts = extensions.flatMap(_.interfaces)
+
+    val ei = extraInts.map(getInterfaceType(origin, _))
+    val oi = tpe.interfaces.map(getInterfaceType(origin, _))
+
+    (ei ++ oi).toList
+  }
+
   def buildFields(
       origin: MatOrigin,
       tpe: TypeDefinition,

modules/core/src/main/scala/sangria/schema/IntrospectionSchemaBuilder.scala

@@ -33,11 +33,18 @@ trait IntrospectionSchemaBuilder[Ctx] {
       mat: IntrospectionSchemaMaterializer[Ctx, _])
       : Option[InputObjectType[InputObjectType.DefaultInput]]
 
+  @deprecated("Interfaces can implement interfaces", "") // TODO put version
   def buildInterfaceType(
       definition: IntrospectionInterfaceType,
       fields: () => List[Field[Ctx, Any]],
       mat: IntrospectionSchemaMaterializer[Ctx, _]): Option[InterfaceType[Ctx, Any]]
 
+  def buildInterfaceType(
+      definition: IntrospectionInterfaceType,
+      fields: () => List[Field[Ctx, Any]],
+      interfaces: List[InterfaceType[Ctx, Any]],
+      mat: IntrospectionSchemaMaterializer[Ctx, _]): Option[InterfaceType[Ctx, Any]]
+
   def buildUnionType(
       definition: IntrospectionUnionType,
       types: List[ObjectType[Ctx, _]],
@@ -158,12 +165,19 @@ class DefaultIntrospectionSchemaBuilder[Ctx] extends IntrospectionSchemaBuilder[
       definition: IntrospectionInterfaceType,
       fields: () => List[Field[Ctx, Any]],
       mat: IntrospectionSchemaMaterializer[Ctx, _]) =
+    buildInterfaceType(definition, fields, List.empty, mat)
+
+  def buildInterfaceType(
+      definition: IntrospectionInterfaceType,
+      fields: () => List[Field[Ctx, Any]],
+      interfaces: List[InterfaceType[Ctx, Any]],
+      mat: IntrospectionSchemaMaterializer[Ctx, _]) =
     Some(
       InterfaceType[Ctx, Any](
         name = typeName(definition),
         description = typeDescription(definition),
         fieldsFn = fields,
-        interfaces = Nil,
+        interfaces = interfaces,
         manualPossibleTypes = () => Nil,
         astDirectives = Vector.empty,
         astNodes = Vector.empty

modules/core/src/main/scala/sangria/schema/IntrospectionSchemaMaterializer.scala

@@ -139,7 +139,11 @@ class IntrospectionSchemaMaterializer[Ctx, T: InputUnmarshaller](
       this)
 
   def buildInterfaceDef(tpe: IntrospectionInterfaceType) =
-    builder.buildInterfaceType(tpe, () => tpe.fields.toList.flatMap(buildField(tpe, _)), this)
+    builder.buildInterfaceType(
+      tpe,
+      () => tpe.fields.toList.flatMap(buildField(tpe, _)),
+      tpe.interfaces.toList.map(getInterfaceType),
+      this)
 
   def buildUnionDef(tpe: IntrospectionUnionType) =
     builder.buildUnionType(tpe, tpe.possibleTypes.toList.map(getObjectType), this)

modules/core/src/test/scala/sangria/renderer/SchemaRenderSpec.scala

@@ -480,7 +480,7 @@ class SchemaRenderSpec
         |  query: Root
         |}
         |
-        |interface Baaz {
+        |interface Baaz implements Foo {
         |  int: Int
         |  str: String
         |}

modules/parser/src/main/scala/sangria/parser/QueryParser.scala

@@ -411,16 +411,19 @@ private[parser] sealed trait TypeSystemDefinitions {
   }
 
   private[this] def InterfaceTypeDefinition = rule {
-    Description ~ Comments ~ trackPos ~ interface ~ Name ~ (DirectivesConst.? ~> (_.getOrElse(
-      Vector.empty))) ~ FieldsDefinition.? ~> ((descr, comment, location, name, dirs, fields) =>
-      ast.InterfaceTypeDefinition(
-        name,
-        fields.fold(Vector.empty[ast.FieldDefinition])(_._1.toVector),
-        dirs,
-        descr,
-        comment,
-        fields.fold(Vector.empty[ast.Comment])(_._2),
-        location))
+    Description ~ Comments ~ trackPos ~ interface ~ Name ~ (ImplementsInterfaces.? ~> (_.getOrElse(
+      Vector.empty))) ~ (DirectivesConst.? ~> (_.getOrElse(Vector.empty))) ~ FieldsDefinition.? ~> (
+      (descr, comment, location, name, interfaces, dirs, fields) =>
+        ast.InterfaceTypeDefinition(
+          name,
+          fields.fold(Vector.empty[ast.FieldDefinition])(_._1.toVector),
+          dirs,
+          descr,
+          comment,
+          fields.fold(Vector.empty[ast.Comment])(_._2),
+          location,
+          interfaces
+        ))
   }
 
   private[this] def UnionTypeDefinition = rule {