improve support for rspec scaffolding (thanks voxik) - closes #176

lib/cancan/controller_resource.rb

@@ -61,20 +61,18 @@ module CanCan
     end
 
     def build_resource
-      if @options[:singleton] && resource_base.respond_to?("build_#{name}")
-        resource = resource_base.send("build_#{name}")
-      else
-        resource = resource_base.send("new")
-      end
+      method_name = @options[:singleton] && resource_base.respond_to?("build_#{name}") ? "build_#{name}" : "new"
+      resource = resource_base.send(method_name, @params[name] || {})
       initial_attributes.each do |name, value|
         resource.send("#{name}=", value)
       end
-      resource.attributes = @params[name] if @params[name]
       resource
     end
 
     def initial_attributes
-      current_ability.attributes_for(@params[:action].to_sym, resource_class)
+      current_ability.attributes_for(@params[:action].to_sym, resource_class).delete_if do |key, value|
+        @params[name] && @params[name].include?(key)
+      end
     end
 
     def find_resource

spec/cancan/controller_resource_spec.rb

@@ -245,7 +245,7 @@ describe CanCan::ControllerResource do
     @params.merge!(:action => "create", :project => {:name => "foobar"})
     category = Object.new
     @controller.instance_variable_set(:@category, category)
-    stub(category).build_project { Project.new }
+    stub(category).build_project { |attributes| Project.new(attributes) }
     resource = CanCan::ControllerResource.new(@controller, :through => :category, :singleton => true)
     resource.load_resource
     @controller.instance_variable_get(:@project).name.should == "foobar"