total rewrite to interface handling; not complete but it compiles

generate/testdata/QueryWithEnums.graphql.go

@@ -1,12 +1,36 @@
-type Response struct {
-	User *struct {
-		Roles []role `json:"roles"`
-	} `json:"user"`
+package test
+
+// Code generated by github.com/Khan/genql, DO NOT EDIT.
+
+import (
+	"context"
+
+	"github.com/Khan/genql/graphql"
+)
+
+type QueryWithEnumsResponse struct {
+	User *User `json:"user"`
 }
 
-type role string
+type Role string
 
 const (
-	studentRole role = "STUDENT"
-	teacherRole role = "TEACHER"
-)
+	StudentRole Role = "STUDENT"
+	TeacherRole Role = "TEACHER"
+)
+
+type User struct {
+	Roles []Role `json:"roles"`
+}
+
+func QueryWithEnums(client *graphql.Client) (*QueryWithEnumsResponse, error) {
+	var retval QueryWithEnumsResponse
+	err := client.MakeRequest(context.Background(), `
+query QueryWithEnums {
+	user {
+		roles
+	}
+}
+`, &retval, nil)
+	return &retval, err
+}