override for JSON formatter

lib/senor_armando/goliath_extensions.rb

@@ -112,3 +112,39 @@ def safely(env, headers={})
 
   end
 end
+require 'multi_json'
+
+module Goliath
+  module Rack
+    module Formatters
+      # A JSON formatter. Uses MultiJson so you can use the JSON
+      # encoder that is right for your project.
+      #
+      # @example
+      #   use Goliath::Rack::Formatters::JSON
+      class JSON
+        include AsyncMiddleware
+
+        def post_process(env, status, headers, body)
+          if self.class.applies_format?(headers)
+            body = self.class.format(body)
+          end
+          [status, headers, body]
+        end
+
+        def json_response?(headers)
+          self.class.applies_format?(headers)
+        end
+
+        def self.format(body)
+          [MultiJson.encode(body)]
+        end
+
+        def self.applies_format?(headers)
+          headers['Content-Type'] =~ %r{^application/(json|javascript)}
+        end
+
+      end
+    end
+  end
+end