[Pleroma.Web.MastodonAPI.FilterView]: expires_at should be null when N/A

lib/pleroma/web/mastodon_api/views/filter_view.ex

@@ -8,11 +8,17 @@ def render("filters.json", %{filters: filters} = opts) do
   end
 
   def render("filter.json", %{filter: filter}) do
+    if filter.expires_at do
+      expires_at = Utils.to_masto_date(filter.expires_at)
+    else
+      expires_at = nil
+    end
+
     %{
       id: to_string(filter.filter_id),
       phrase: filter.phrase,
       context: filter.context,
-      expires_at: Utils.to_masto_date(filter.expires_at),
+      expires_at: expires_at,
       irreversible: filter.hide,
       whole_word: false
     }