From 811750d2e98c3222b96245eb7081f8ee6325e060 Mon Sep 17 00:00:00 2001
From: Zack Michener <z@zjm.me>
Date: Thu, 22 Feb 2024 12:04:09 -0800
Subject: [PATCH] Transform relationship keys with shallow field transformation
 options

---
 lib/jsonapi/utils/string.ex      | 4 ++++
 test/jsonapi/serializer_test.exs | 3 +++
 2 files changed, 7 insertions(+)

diff --git a/lib/jsonapi/utils/string.ex b/lib/jsonapi/utils/string.ex
index bbe308df..aa5b7f56 100644
--- a/lib/jsonapi/utils/string.ex
+++ b/lib/jsonapi/utils/string.ex
@@ -261,6 +261,10 @@ defmodule JSONAPI.Utils.String do
     end)
   end
 
+  def expand_root_keys(key, fun) when is_binary(key) or is_atom(key) do
+    fun.(key)
+  end
+
   def expand_root_keys(value, _fun), do: expand_fields(value, &to_string/1)
 
   defp maybe_expand_fields(values, fun) when is_list(values) do
diff --git a/test/jsonapi/serializer_test.exs b/test/jsonapi/serializer_test.exs
index 65543c3f..14cb113c 100644
--- a/test/jsonapi/serializer_test.exs
+++ b/test/jsonapi/serializer_test.exs
@@ -667,12 +667,15 @@ defmodule JSONAPI.SerializerTest do
       encoded = Serializer.serialize(PostView, data, nil)
 
       attributes = encoded[:data][:attributes]
+      relationships = encoded[:data][:relationships]
       included = encoded[:included]
 
       assert attributes["full-description"] == data[:full_description]
       assert attributes["body"]["data_attr"] == "foo"
       assert attributes["inserted-at"] == data[:inserted_at]
 
+      assert Map.has_key?(relationships, "best-comments")
+
       author = Enum.find(included, &(&1[:type] == "user" && &1[:id] == "2"))
       assert author != nil
       assert author[:attributes]["last-name"] == "bonds"