class SassC::Engine

def post_process_source_map(source_map)
  return unless source_map
  url = URL.parse(source_map_file_url || file_url)
  data = JSON.parse(source_map)
  data['file'] = URL.parse(output_url).route_from(url).to_s if output_url
  data['sources'].map! do |source|
    if source.start_with?('file:')
      URL.parse(source).route_from(url).to_s
    else
      source
    end
  end
  JSON.generate(data)
end