Schema validation: interfaces #229

core/src/main/scala/caliban/validation/Validator.scala

@@ -31,9 +31,10 @@ object Validator {
   def validateSchema(rootType: RootType): IO[ValidationError, Unit] =
     IO.foreach(rootType.types.values) { t =>
         t.kind match {
-          case __TypeKind.ENUM  => validateEnum(t)
-          case __TypeKind.UNION => validateUnion(t)
-          case _                => IO.unit
+          case __TypeKind.ENUM      => validateEnum(t)
+          case __TypeKind.UNION     => validateUnion(t)
+          case __TypeKind.INTERFACE => validateInterface(t)
+          case _                    => IO.unit
         }
       }
       .unit
@@ -563,6 +564,60 @@ object Validator {
         )
     }
 
+  private def validateInterface(t: __Type): IO[ValidationError, Unit] = {
+    def validateName(name: String) = {
+      if (name.isEmpty) {
+        IO.fail(ValidationError("msg", "explanatory"))
+      } else if (name.startsWith("__")) {
+        IO.fail(ValidationError("msg", "explanatory"))
+      } else {
+        IO.unit
+      }
+    }
+    def validateFieldName(field: __Field): IO[ValidationError, Unit] = {
+      validateName(field.name)
+    }
+    def validateFieldArgumentsName(args: List[__InputValue]): IO[ValidationError, Unit] = {
+      IO.foreach(args){ arg => validateName(arg.name) }.unit
+    }
+
+    def validateFieldReturnOutputType(`type`: () => __Type): IO[ValidationError, Unit]       = IO.unit
+    def validateFieldArgumentsInputType(args: List[__InputValue]): IO[ValidationError, Unit] = IO.unit
+
+    def validateInterfaceField(field: __Field): IO[ValidationError, Unit] =
+      for {
+        _ <- validateFieldName(field)
+        _ <- validateFieldReturnOutputType(field.`type`)
+        _ <- validateFieldArgumentsName(field.args)
+        _ <- validateFieldArgumentsInputType(field.args)
+      } yield ()
+
+    def duplicateFieldName(fields: List[__Field]): Option[__Field] =
+      fields.groupBy(_.name).collectFirst { case (_, f :: _ :: _) => f }
+
+    t.fields(__DeprecatedArgs(Some(true))) match {
+      case None | Some(Nil) =>
+        IO.fail(
+          ValidationError(
+            s"message",
+            "explanatory"
+          )
+        )
+      case Some(fields) =>
+        duplicateFieldName(fields) match {
+          case Some(value) =>
+            IO.fail(
+              ValidationError(
+                s"message with $value",
+                "explanatory"
+              )
+            )
+          case None =>
+            IO.foreach(fields){ validateInterfaceField }.unit
+        }
+    }
+  }
+
   private def validateUnion(t: __Type): IO[ValidationError, Unit] = {
 
     def isObject(t: __Type): Boolean = t.kind match {