Simplify the nulls last case statement.

Author: natebird

lib/ajax-datatables-rails/datatable/simple_order.rb

@@ -43,9 +43,9 @@ def nulls_last_sql
         return unless sort_nulls_last?
 
         case AjaxDatatablesRails.config.db_adapter
-        when -> (a) { a.in?([:pg, :postgresql, :postgres, :oracle]) }
+        when :pg, :postgresql, :postgres, :oracle
           "NULLS LAST"
-        when -> (a) { a.in?([:mysql, :mysql2, :sqlite, :sqlite3]) }
+        when :mysql, :mysql2, :sqlite, :sqlite3
           "IS NULL"
         else
           raise 'unsupported database adapter'

spec/support/test_helpers.rb

@@ -100,9 +100,9 @@ def data
 
 def nulls_last_sql
   case AjaxDatatablesRails.config.db_adapter
-  when -> (a) { a.in?([:pg, :postgresql, :postgres, :oracle]) }
+  when :pg, :postgresql, :postgres, :oracle
     "NULLS LAST"
-  when -> (a) { a.in?([:mysql, :mysql2, :sqlite, :sqlite3]) }
+  when :mysql, :mysql2, :sqlite, :sqlite3
     "IS NULL"
   else
     raise 'unsupported database adapter'