Add item label class option for collection inputs.

This allows checkbox and radio collections to be styled with the checkbox-inline and radio-inline styles from boostrap 3 when paired with setting the item wrapper tag to false.

lib/simple_form/tags.rb

@@ -19,6 +19,7 @@ module SimpleForm
             label_options = {}
             add_default_name_and_id_for_value(value, label_options)
             label_options['for'] = label_options.delete('id')
+            label_options['class'] = @options.fetch(:item_label_class, '')
             rendered_item = content_tag(:label, rendered_item, label_options)
           end
 

test/inputs/collection_check_boxes_input_test.rb

@@ -245,6 +245,23 @@ class CollectionCheckBoxesInputTest < ActionView::TestCase
     end
   end
 
+  test 'input check boxes with nested style renders item labels with specified class' do
+    swap SimpleForm, boolean_style: :nested do
+      with_input_for @user, :active, :check_boxes, item_label_class: "test"
+
+      assert_select 'span.checkbox > label.test > input'
+    end
+  end
+
+  test 'input check boxes with nested style and falsey input wrapper renders item labels with specified class' do
+    swap SimpleForm, boolean_style: :nested, item_wrapper_tag: false do
+      with_input_for @user, :active, :check_boxes, item_label_class: "checkbox-inline"
+
+      assert_select 'label.checkbox-inline > input'
+      assert_no_select 'span.checkbox'
+    end
+  end
+
   test 'input check boxes wrapper class are not included when set to falsey' do
     swap SimpleForm, include_default_input_wrapper_class: false, boolean_style: :nested do
       with_input_for @user, :gender, :check_boxes, collection: [:male, :female]

test/inputs/collection_radio_buttons_input_test.rb

@@ -368,6 +368,23 @@ class CollectionRadioButtonsInputTest < ActionView::TestCase
     end
   end
 
+  test 'input radio with nested style renders item labels with specified class' do
+    swap SimpleForm, boolean_style: :nested do
+      with_input_for @user, :active, :radio_buttons, item_label_class: "test"
+
+      assert_select 'span.radio > label.test > input'
+    end
+  end
+
+  test 'input radio with nested style and falsey input wrapper renders item labels with specified class' do
+    swap SimpleForm, boolean_style: :nested, item_wrapper_tag: false do
+      with_input_for @user, :active, :radio_buttons, item_label_class: "radio-inline"
+
+      assert_select 'label.radio-inline > input'
+      assert_no_select 'span.radio'
+    end
+  end
+
   test 'input radio wrapper class are not included when set to falsey' do
     swap SimpleForm, include_default_input_wrapper_class: false, boolean_style: :nested do
       with_input_for @user, :gender, :radio_buttons, collection: [:male, :female]