a fix for performance improvement for the javascript_include_tag

gistfile1.rb

# fix assets loading performance in 3.2.13 
# see:
# * https://github.com/rails/rails/commit/687e68d88f5e1a7bb6a2d876fbbc5b8c4571d853
# * https://github.com/rails/rails/issues/9803
if Rails.env.development? && Rails.version == "3.2.13"
  module Sprockets
    module Helpers
      module RailsHelper
        class AssetPaths
          def rewrite_extension(source, dir, ext)
            source_ext = File.extname(source)[1..-1]

            if !ext || ext == source_ext
              source
            elsif source_ext.blank?
              "#{source}.#{ext}"
            elsif File.exists?(source) || exact_match_present?(source)
              source
            else
              "#{source}.#{ext}"
            end
          end
        end
      end
    end
  end
end