Also fix 'to_json' in struct Video

src/invidious/helpers/helpers.cr

@@ -206,7 +206,7 @@ def create_notification_stream(env, topics, connection_channel)
 
           video = get_video(video_id, PG_DB)
           video.published = published
-          response = JSON.parse(video.to_json(locale))
+          response = JSON.parse(video.to_json(locale, nil))
 
           if fields_text = env.params.query["fields"]?
             begin
@@ -282,7 +282,7 @@ def create_notification_stream(env, topics, connection_channel)
 
         video = get_video(video_id, PG_DB)
         video.published = Time.unix(published)
-        response = JSON.parse(video.to_json(locale))
+        response = JSON.parse(video.to_json(locale, nil))
 
         if fields_text = env.params.query["fields"]?
           begin

src/invidious/routes/api/v1/videos.cr

@@ -16,7 +16,7 @@ module Invidious::Routes::API::V1::Videos
       return error_json(500, ex)
     end
 
-    video.to_json(locale)
+    video.to_json(locale, nil)
   end
 
   def self.captions(env)

src/invidious/videos.cr

@@ -275,7 +275,7 @@ struct Video
     end
   end
 
-  def to_json(locale : Hash(String, JSON::Any), json : JSON::Builder)
+  def to_json(locale : Hash(String, JSON::Any) | Nil, json : JSON::Builder)
     json.object do
       json.field "type", "video"
 
@@ -474,14 +474,13 @@ struct Video
     end
   end
 
-  def to_json(locale, json : JSON::Builder | Nil = nil)
-    if json
-      to_json(locale, json)
-    else
-      JSON.build do |json|
-        to_json(locale, json)
-      end
-    end
+  # TODO: remove the locale and follow the crystal convention
+  def to_json(locale : Hash(String, JSON::Any) | Nil, _json : Nil)
+    JSON.build { |json| to_json(locale, json) }
+  end
+
+  def to_json(json : JSON::Builder | Nil = nil)
+    to_json(nil, json)
   end
 
   def title