Add default css class to button, closes #36

lib/simple_form/form_builder.rb

@@ -159,6 +159,9 @@ module SimpleForm
     # It just acts as a proxy to method name given.
     #
     def button(type, *args, &block)
+      options = args.extract_options!
+      options[:class] = "button #{options[:class]}".strip
+      args << options
       if respond_to?(:"#{type}_button")
         send(:"#{type}_button", *args, &block)
       else

test/form_builder_test.rb

@@ -394,13 +394,13 @@ class FormBuilderTest < ActionView::TestCase
   # BUTTONS
   test 'builder should create buttons' do
     with_button_for :post, :submit
-    assert_select 'form input[type=submit][value=Save Post]'
+    assert_select 'form input.button[type=submit][value=Save Post]'
   end
 
   test 'builder should create buttons for records' do
     @user.new_record!
     with_button_for @user, :submit
-    assert_select 'form input[type=submit][value=Create User]'
+    assert_select 'form input.button[type=submit][value=Create User]'
   end
 
   # ASSOCIATIONS