Collections of strings in CheckBoxesInput should now be checked if th…

…ey match the model.

A String responds to methods such as :first and :last, so instead of applying send_or_call to the String ("hello".last => "o"), simply return the String itself.

Fixes formtastic#630, Ref formtastic#619

lib/formtastic/inputs/base/collections.rb

@@ -87,6 +87,13 @@ def send_or_call(duck, object)
             object.send(duck)
           end
         end
+
+        # Avoids an issue where `send_or_call` can be a String and duck can be something simple like
+        # `:first`, which obviously String responds to.
+        def send_or_call_or_object(duck, object)
+          return object if object.is_a?(String) # TODO what about other classes etc?
+          send_or_call(duck, object)
+        end
 
       end
     end

lib/formtastic/inputs/check_boxes_input.rb

@@ -154,7 +154,7 @@ def disabled?(value)
       def selected_values
         if object.respond_to?(method)
           selected_items = [object.send(method)].compact.flatten
-          [*selected_items.map { |o| send_or_call(value_method, o) }].compact
+          [*selected_items.map { |o| send_or_call_or_object(value_method, o) }].compact
         else
           []
         end

spec/inputs/check_boxes_input_spec.rb

@@ -361,7 +361,7 @@
     before do
       @output_buffer = ''
       mock_everything
-      @fred.stub(:genres) { ['ficton', 'biography'] }
+      @fred.stub(:genres) { ['fiction', 'biography'] }
 
       concat(semantic_form_for(@fred) do |builder|
         concat(builder.input(:genres, :as => :check_boxes, :collection => [['Fiction', 'fiction'], ['Non-fiction', 'non_fiction'], ['Biography', 'biography']]))