supporting symbols for group statements

lib/arel/select_manager.rb

@@ -43,6 +43,7 @@ module Arel
       columns.each do |column|
         # FIXME: backwards compat
         column = Nodes::SqlLiteral.new(column) if String === column
+        column = Nodes::SqlLiteral.new(column.to_s) if Symbol === column
 
         @ctx.groups.push Nodes::Group.new column
       end

spec/arel/select_manager_spec.rb

@@ -27,6 +27,18 @@ module Arel
 
   describe 'select manager' do
     describe 'backwards compatibility' do
+      describe 'group' do
+        it 'takes a symbol' do
+          table   = Table.new :users
+          manager = Arel::SelectManager.new Table.engine
+          manager.from table
+          manager.group :foo
+          manager.to_sql.should be_like %{
+          SELECT FROM "users" GROUP BY foo
+          }
+        end
+      end
+
       describe 'from' do
         it 'ignores strings when table of same name exists' do
           table   = Table.new :users