From 2d8240e2024d58c4f07bc0bd49f30e62fdb941e5 Mon Sep 17 00:00:00 2001
From: "Gregory N. Schmit" <schmitgreg@gmail.com>
Date: Mon, 3 Apr 2023 01:02:11 -0500
Subject: [PATCH] Fix Rails 6.0 'url delegated to attachment but attachment is
 nil'.

---
 lib/rest_framework/serializers.rb | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/rest_framework/serializers.rb b/lib/rest_framework/serializers.rb
index ce2d590..d0b11bd 100644
--- a/lib/rest_framework/serializers.rb
+++ b/lib/rest_framework/serializers.rb
@@ -277,11 +277,11 @@ def _get_controller_serializer_config(fields)
         serializer_methods[f] = f
         if ref.macro == :has_one_attached
           self.define_singleton_method(f) do |record|
-            next record.send(f).url
+            next record.send(f).attachment&.url
           end
         else
           self.define_singleton_method(f) do |record|
-            next record.send(f).map(&:url)
+            next record.send(f).map { |x| x.attachment&.url }
           end
         end
       elsif @model.method_defined?(f)