Fix specs.

lib/pleroma/web/activity_pub/activity_pub.ex

@@ -139,6 +139,7 @@ defp restrict_tag(query, %{"tag" => tag}) do
   end
   defp restrict_tag(query, _), do: query
 
+  defp restrict_recipients(query, []), do: query
   defp restrict_recipients(query, recipients) do
     from activity in query,
      where: fragment("? && ?", ^recipients, activity.recipients)

test/support/factory.ex

@@ -52,7 +52,8 @@ def note_activity_factory do
 
     %Pleroma.Activity{
       data: data,
-      actor: data["actor"]
+      actor: data["actor"],
+      recipients: data["to"]
     }
   end