total rewrite to interface handling; not complete but it compiles

generate/testdata/QueryWithStructs.graphql.go

@@ -1,8 +1,37 @@
-type Response struct {
-	User *struct {
-		AuthMethods []struct {
-			Provider *string `json:"provider"`
-			Email    *string `json:"email"`
-		} `json:"authMethods"`
-	} `json:"user"`
-}
+package test
+
+// Code generated by github.com/Khan/genql, DO NOT EDIT.
+
+import (
+	"context"
+
+	"github.com/Khan/genql/graphql"
+)
+
+type AuthMethod struct {
+	Provider *string `json:"provider"`
+	Email    *string `json:"email"`
+}
+
+type QueryWithStructsResponse struct {
+	User *User `json:"user"`
+}
+
+type User struct {
+	AuthMethods []AuthMethod `json:"authMethods"`
+}
+
+func QueryWithStructs(client *graphql.Client) (*QueryWithStructsResponse, error) {
+	var retval QueryWithStructsResponse
+	err := client.MakeRequest(context.Background(), `
+query QueryWithStructs {
+	user {
+		authMethods {
+			provider
+			email
+		}
+	}
+}
+`, &retval, nil)
+	return &retval, err
+}