add field_with_hint class to the input with hint wrappers, closes #323

lib/generators/simple_form/templates/config/initializers/simple_form.rb

@@ -4,7 +4,7 @@ SimpleForm.setup do |config|
   # You can remove any component from the wrapper, change the order or even
   # add your own to the stack. The options given to the wrappers method
   # are used to wrap the whole input.
-  config.wrappers :class => :input, :error_class => :field_with_errors do |b|
+  config.wrappers :class => :input, :hint_class => :field_with_hint, :error_class => :field_with_errors do |b|
     ## Extensions
     # Determines whether to use HTML5 (:email, :url, :search, :tel) and required attributes
     b.use :html5

lib/simple_form.rb

@@ -144,7 +144,7 @@ module SimpleForm
     SimpleForm::Wrappers::Root.new(builder.to_a, options)
   end
 
-  wrappers :class => :input, :error_class => :field_with_errors do |b|
+  wrappers :class => :input, :hint_class => :field_with_hint, :error_class => :field_with_errors do |b|
     b.use :html5
 
     b.use :min_max

lib/simple_form/wrappers/root.rb

@@ -26,6 +26,7 @@ module SimpleForm
         css = options[:wrapper_class] ? Array.wrap(options[:wrapper_class]) : @defaults[:class]
         css += input.html_classes
         css << (options[:wrapper_error_class] || @defaults[:error_class]) if input.has_errors?
+        css << (options[:wrapper_hint_class] || @defaults[:hint_class]) if input.hint
         css
       end
     end

test/form_builder/wrapper_test.rb

@@ -16,6 +16,11 @@ class WrapperTest < ActionView::TestCase
     assert_select 'div.field_with_errors'
   end
 
+  test 'wrapper should add hint class for attribute with a hint' do
+    with_form_for @user, :name, :hint => 'hint'
+    assert_select 'div.field_with_hint'
+  end
+
   test 'wrapper should not have disabled class by default' do
     with_form_for @user, :active
     assert_no_select 'div.disabled'