Params are optional in in apply_sort

Author: guillaumebriday

README.md

@@ -72,6 +72,7 @@ You can use `apply_sort` in your controller :
 class ContactsController < ApplicationController
   def index
     @contacts = Contact.apply_sort(params)
+    @contacts = Contact.apply_sort # to only apply default sort
   end
 end
 ```

lib/jsonapi/scopes/sorts.rb

@@ -18,7 +18,7 @@ def sortable_fields(*fields)
         @sortable_fields = fields
       end
 
-      def apply_sort(params, options = { allowed: [], default: {} })
+      def apply_sort(params = {}, options = { allowed: [], default: {} })
         fields = params.dig(:sort)
 
         allowed_fields = [options[:allowed]].flatten.presence || @sortable_fields