Add support for interface implementing interface

build.sbt

@@ -71,7 +71,43 @@ lazy val ast = project
       ProblemFilters.exclude[DirectMissingMethodProblem]("sangria.ast.DirectiveDefinition.apply"),
       ProblemFilters.exclude[DirectMissingMethodProblem]("sangria.ast.DirectiveDefinition.copy"),
       ProblemFilters.exclude[DirectMissingMethodProblem]("sangria.ast.DirectiveDefinition.this"),
-      ProblemFilters.exclude[MissingTypesProblem]("sangria.ast.DirectiveDefinition$")
+      ProblemFilters.exclude[MissingTypesProblem]("sangria.ast.DirectiveDefinition$"),
+      ProblemFilters.exclude[IncompatibleResultTypeProblem](
+        "sangria.introspection.IntrospectionInterfaceType.*"),
+      ProblemFilters.exclude[DirectMissingMethodProblem](
+        "sangria.introspection.IntrospectionInterfaceType.this"),
+      ProblemFilters.exclude[DirectMissingMethodProblem](
+        "sangria.introspection.IntrospectionInterfaceType.copy"),
+      ProblemFilters.exclude[MissingTypesProblem]("sangria.ast.InterfaceTypeDefinition$"),
+      ProblemFilters.exclude[IncompatibleResultTypeProblem](
+        "sangria.ast.InterfaceTypeDefinition.*"),
+      ProblemFilters.exclude[DirectMissingMethodProblem](
+        "sangria.ast.InterfaceTypeDefinition.this"),
+      ProblemFilters.exclude[DirectMissingMethodProblem](
+        "sangria.ast.InterfaceTypeDefinition.copy"),
+      ProblemFilters.exclude[DirectMissingMethodProblem](
+        "sangria.ast.InterfaceTypeDefinition.tupled"),
+      ProblemFilters.exclude[DirectMissingMethodProblem](
+        "sangria.ast.InterfaceTypeDefinition.curried"),
+      ProblemFilters.exclude[DirectMissingMethodProblem](
+        "sangria.ast.InterfaceTypeDefinition.<init>*"),
+      ProblemFilters.exclude[DirectMissingMethodProblem](
+        "sangria.ast.InterfaceTypeDefinition.apply$default$*"),
+      ProblemFilters.exclude[MissingTypesProblem]("sangria.ast.InterfaceTypeExtensionDefinition$"),
+      ProblemFilters.exclude[IncompatibleResultTypeProblem](
+        "sangria.ast.InterfaceTypeExtensionDefinition.*"),
+      ProblemFilters.exclude[DirectMissingMethodProblem](
+        "sangria.ast.InterfaceTypeExtensionDefinition.this"),
+      ProblemFilters.exclude[DirectMissingMethodProblem](
+        "sangria.ast.InterfaceTypeExtensionDefinition.copy"),
+      ProblemFilters.exclude[DirectMissingMethodProblem](
+        "sangria.ast.InterfaceTypeExtensionDefinition.tupled"),
+      ProblemFilters.exclude[DirectMissingMethodProblem](
+        "sangria.ast.InterfaceTypeExtensionDefinition.curried"),
+      ProblemFilters.exclude[DirectMissingMethodProblem](
+        "sangria.ast.InterfaceTypeExtensionDefinition.<init>*"),
+      ProblemFilters.exclude[DirectMissingMethodProblem](
+        "sangria.ast.InterfaceTypeExtensionDefinition.apply$default$*")
     ),
     apiURL := {
       val ver = CrossVersion.binaryScalaVersion(scalaVersion.value)
@@ -140,7 +176,23 @@ lazy val core = project
       ProblemFilters.exclude[DirectMissingMethodProblem]("sangria.schema.Field.subs"),
       ProblemFilters.exclude[DirectMissingMethodProblem]("sangria.schema.Field.apply"),
       ProblemFilters.exclude[DirectMissingMethodProblem]("sangria.execution.Resolver.*"),
-      ProblemFilters.exclude[DirectMissingMethodProblem]("sangria.execution.Resolver#*")
+      ProblemFilters.exclude[DirectMissingMethodProblem]("sangria.execution.Resolver#*"),
+      ProblemFilters.exclude[ReversedMissingMethodProblem](
+        "sangria.schema.AstSchemaBuilder.buildInterfaceType"),
+      ProblemFilters.exclude[ReversedMissingMethodProblem](
+        "sangria.schema.AstSchemaBuilder.extendInterfaceType"),
+      ProblemFilters.exclude[ReversedMissingMethodProblem](
+        "sangria.schema.IntrospectionSchemaBuilder.buildInterfaceType"),
+      ProblemFilters.exclude[MissingTypesProblem](
+        "sangria.introspection.IntrospectionInterfaceType$"),
+      ProblemFilters.exclude[DirectMissingMethodProblem](
+        "sangria.introspection.IntrospectionInterfaceType.this"),
+      ProblemFilters.exclude[DirectMissingMethodProblem](
+        "sangria.introspection.IntrospectionInterfaceType.tupled"),
+      ProblemFilters.exclude[DirectMissingMethodProblem](
+        "sangria.introspection.IntrospectionInterfaceType.curried"),
+      ProblemFilters.exclude[DirectMissingMethodProblem](
+        "sangria.introspection.IntrospectionInterfaceType.copy")
     ),
     Test / testOptions += Tests.Argument(TestFrameworks.ScalaTest, "-oF"),
     libraryDependencies ++= Seq(

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

@@ -530,6 +530,7 @@ case class ObjectTypeDefinition(
 case class InterfaceTypeDefinition(
     name: String,
     fields: Vector[FieldDefinition],
+    interfaces: Vector[NamedType],
     directives: Vector[Directive] = Vector.empty,
     description: Option[StringValue] = None,
     comments: Vector[Comment] = Vector.empty,
@@ -541,6 +542,27 @@ case class InterfaceTypeDefinition(
   def rename(newName: String): InterfaceTypeDefinition = copy(name = newName)
 }
 
+object InterfaceTypeDefinition {
+
+  def apply(
+      name: String,
+      fields: Vector[FieldDefinition],
+      directives: Vector[Directive],
+      description: Option[StringValue],
+      comments: Vector[Comment],
+      trailingComments: Vector[Comment],
+      location: Option[AstLocation]): InterfaceTypeDefinition = new InterfaceTypeDefinition(
+    name,
+    fields,
+    Vector.empty,
+    directives,
+    description,
+    comments,
+    trailingComments,
+    location
+  )
+}
+
 /** @group typesystem
   */
 case class UnionTypeDefinition(
@@ -619,15 +641,38 @@ case class ObjectTypeExtensionDefinition(
 case class InterfaceTypeExtensionDefinition(
     name: String,
     fields: Vector[FieldDefinition],
+    interfaces: Vector[NamedType],
     directives: Vector[Directive] = Vector.empty,
     comments: Vector[Comment] = Vector.empty,
     trailingComments: Vector[Comment] = Vector.empty,
     location: Option[AstLocation] = None)
     extends ObjectLikeTypeExtensionDefinition
     with WithTrailingComments {
+
   def rename(newName: String): InterfaceTypeExtensionDefinition = copy(name = newName)
 }
 
+object InterfaceTypeExtensionDefinition {
+
+  def apply(
+      name: String,
+      fields: Vector[FieldDefinition],
+      directives: Vector[Directive],
+      comments: Vector[Comment],
+      trailingComments: Vector[Comment],
+      location: Option[AstLocation]): InterfaceTypeExtensionDefinition =
+    InterfaceTypeExtensionDefinition(
+      name,
+      fields,
+      Vector.empty,
+      directives,
+      comments,
+      trailingComments,
+      location
+    )
+
+}
+
 /** @group typesystem
   */
 case class InputObjectTypeExtensionDefinition(

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, $p)"
+    case InterfaceTypeExtensionDefinition(n, f, i, d, c, tc, p) =>
+      q"_root_.sangria.ast.InterfaceTypeExtensionDefinition($n, $f, $i, $d, $c, $tc, $p)"
     case InputObjectTypeExtensionDefinition(n, f, d, c, tc, p) =>
       q"_root_.sangria.ast.InputObjectTypeExtensionDefinition($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, $p)"
+    case InterfaceTypeDefinition(n, f, i, d, desc, c, tc, p) =>
+      q"_root_.sangria.ast.InterfaceTypeDefinition($n, $f, $i, $d, $desc, $c, $tc, $p)"
     case ObjectTypeDefinition(n, i, f, d, desc, c, tc, p) =>
       q"_root_.sangria.ast.ObjectTypeDefinition($n, $i, $f, $d, $desc, $c, $tc, $p)"
     case ScalarTypeDefinition(n, d, desc, c, p) =>

modules/core/src/main/scala-3/sangria/macros/ToExprGivens.scala

@@ -158,15 +158,17 @@ trait ToExprGivens {
             ${ Expr(tc) },
             ${ Expr(p) })
         }
-      case InterfaceTypeExtensionDefinition(n, f, d, c, tc, p) =>
+      case InterfaceTypeExtensionDefinition(n, f, i, d, c, tc, p) =>
         '{
           sangria.ast.InterfaceTypeExtensionDefinition(
             ${ Expr(n) },
             ${ Expr(f) },
+            ${ Expr(i) },
             ${ Expr(d) },
             ${ Expr(c) },
             ${ Expr(tc) },
-            ${ Expr(p) })
+            ${ Expr(p) }
+          )
         }
       case InputObjectTypeExtensionDefinition(n, f, d, c, tc, p) =>
         '{
@@ -237,16 +239,18 @@ trait ToExprGivens {
             ${ Expr(tc) },
             ${ Expr(p) })
         }
-      case InterfaceTypeDefinition(n, f, d, desc, c, tc, p) =>
+      case InterfaceTypeDefinition(n, f, i, d, desc, c, tc, p) =>
         '{
           sangria.ast.InterfaceTypeDefinition(
             ${ Expr(n) },
             ${ Expr(f) },
+            ${ Expr(i) },
             ${ Expr(d) },
             ${ Expr(desc) },
             ${ Expr(c) },
             ${ Expr(tc) },
-            ${ Expr(p) })
+            ${ Expr(p) }
+          )
         }
       case ObjectTypeDefinition(n, i, f, d, desc, c, tc, p) =>
         '{

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

@@ -306,12 +306,14 @@ object AstVisitor {
         case n @ InterfaceTypeDefinition(
               _,
               fields,
+              interfaces,
               dirs,
               description,
               comment,
               trailingComments,
               _) =>
           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, ints, dirs, comment, tc, _) =>
           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

@@ -61,9 +61,21 @@ case class IntrospectionInterfaceType(
     name: String,
     description: Option[String],
     fields: Seq[IntrospectionField],
-    possibleTypes: Seq[IntrospectionNamedTypeRef])
-    extends IntrospectionType {
+    interfaces: Seq[IntrospectionNamedTypeRef],
+    possibleTypes: Seq[IntrospectionNamedTypeRef]
+) extends IntrospectionType {
+
   val kind = TypeKind.Interface
+
+}
+
+object IntrospectionInterfaceType {
+  def apply(
+      name: String,
+      description: Option[String],
+      fields: Seq[IntrospectionField],
+      possibleTypes: Seq[IntrospectionNamedTypeRef]): IntrospectionInterfaceType =
+    IntrospectionInterfaceType(name, description, fields, Seq.empty, possibleTypes)
 }
 
 case class IntrospectionUnionType(

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

@@ -272,10 +272,8 @@ package object introspection {
           "interfaces",
           OptionType(ListType(__Type)),
           resolve = _.value._2 match {
-            case t: ObjectType[_, _] =>
+            case t: ObjectLikeType[_, _] =>
               Some(t.allInterfaces.asInstanceOf[Vector[Type]].map(true -> _))
-            case _: InterfaceType[_, _] =>
-              Some(Vector.empty)
             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, interfaces, dirs, description, _, _, _) =>
         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, interfaces, dirs, _, _, _) =>
         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 +220,25 @@ object SchemaRenderer {
     ast.InterfaceTypeDefinition(
       tpe.name,
       renderFieldsI(tpe.fields),
-      description = renderDescription(tpe.description))
+      renderImplementedInterfaces(tpe),
+      Vector.empty,
+      renderDescription(tpe.description),
+      Vector.empty,
+      Vector.empty,
+      None
+    )
 
   def renderInterface(tpe: InterfaceType[_, _]) =
     ast.InterfaceTypeDefinition(
       tpe.name,
       renderFields(tpe.uniqueFields),
+      renderImplementedInterfaces(tpe),
       tpe.astDirectives,
-      renderDescription(tpe.description))
+      renderDescription(tpe.description),
+      Vector.empty,
+      Vector.empty,
+      None
+    )
 
   def renderUnion(tpe: IntrospectionUnionType) =
     ast.UnionTypeDefinition(