Add validation of interfaces defined on each model/union (#950)

Author: mbryzek

build.sbt

@@ -105,6 +105,7 @@ lazy val api = project
   scalacOptions ++= Seq("-deprecation:false"),
     scalacOptions ++= allScalacOptions,
     PlayKeys.fileWatchService := play.dev.filewatch.FileWatchService.jdk7(play.sbt.run.toLoggerProxy(sLog.value)),
+    PlayKeys.playDefaultPort := 9001,
     testOptions += Tests.Argument("-oF"),
     javaAgents += "com.datadoghq" % "dd-java-agent" % "1.8.0",
     routesImport += "io.apibuilder.api.v0.Bindables.Core._",
@@ -144,6 +145,7 @@ lazy val app = project
   .settings(
     scalacOptions ++= allScalacOptions,
     PlayKeys.fileWatchService := play.dev.filewatch.FileWatchService.jdk7(play.sbt.run.toLoggerProxy(sLog.value)),
+    PlayKeys.playDefaultPort := 9000,
     javaAgents += "com.datadoghq" % "dd-java-agent" % "1.8.0",
     routesImport += "io.apibuilder.api.v0.Bindables.Core._",
     routesImport += "io.apibuilder.api.v0.Bindables.Models._",

core/app/builder/api_json/ApiJsonServiceValidator.scala

@@ -92,8 +92,8 @@ case class ApiJsonServiceValidator(
       validateHeaders(form.headers),
       validateResources(form.resources),
       validateInterfaces(form.interfaces),
-      validateUnions(form.unions),
-      validateModels(form.models),
+      validateUnions(form),
+      validateModels(form),
       validateEnums(form.enums),
       validateAnnotations(form.annotations),
       DuplicateJsonParser.validateDuplicates(rawInput)
@@ -126,11 +126,13 @@ case class ApiJsonServiceValidator(
     )
   }
 
-  private def validateUnions(unions: Seq[InternalUnionForm]): ValidatedNec[String, Unit] = {
+  private def validateUnions(form: InternalApiJsonForm): ValidatedNec[String, Unit] = {
     sequenceUnique(
-      unions.map(_.warnings) ++ unions.map { union =>
-        validateAttributes(s"Union[${union.name}]", union.attributes)
-      } ++ unions.map(validateUnionTypes)
+      form.unions.map(_.warnings) ++ form.unions.map { union =>
+        (validateAttributes(s"Union[${union.name}]", union.attributes),
+          validateTypeInterfaces(form, s"Union[${union.name}]", union.interfaces)
+        ).mapN { case (_, _) => () }
+      } ++ form.unions.map(validateUnionTypes)
     )
   }
 
@@ -180,14 +182,26 @@ case class ApiJsonServiceValidator(
     )
   }
 
-  private def validateModels(models: Seq[InternalModelForm]): ValidatedNec[String, Unit] = {
+  private def validateModels(form: InternalApiJsonForm): ValidatedNec[String, Unit] = {
     sequenceUnique(
-      models.map(_.warnings) ++ models.map { model =>
-        validateAttributes(s"Model[${model.name}]", model.attributes)
-      } ++ Seq(validateFields(models))
+      form.models.map(_.warnings) ++ form.models.map { model =>
+        (validateAttributes(s"Model[${model.name}]", model.attributes),
+          validateTypeInterfaces(form, s"Model[${model.name}]", model.interfaces)
+        ).mapN { case (_, _) => () }
+      } ++ Seq(validateFields(form.models))
     )
   }
 
+  private def validateTypeInterfaces(form: InternalApiJsonForm, name: String, interfaces: Seq[String]): ValidatedNec[String, Unit] = {
+    interfaces.map { iName =>
+      if (form.interfaces.exists(_.name == iName)) {
+        ().validNec
+      } else {
+        s"$name cannot find interface named '$iName'".invalidNec
+      }
+    }.sequence.map { _ => () }
+  }
+
   private def validateHeaders(headers: Seq[InternalHeaderForm]): ValidatedNec[String, Unit] = {
     sequenceUnique(
       headers.map(_.warnings) ++ headers.filter(_.name.isDefined).map { header =>