class Sprockets::SourceMapCommentProcessor

def self.call(input)
  case input[:content_type]
  when "application/javascript"
    comment = "\n//# sourceMappingURL=%s"
    map_type = "application/js-sourcemap+json"
  when "text/css"
    comment = "\n/*# sourceMappingURL=%s */"
    map_type = "application/css-sourcemap+json"
  else
    fail input[:content_type]
  end
  env = input[:environment]
  uri, _ = env.resolve!(input[:filename], accept: input[:content_type])
  asset = env.load(uri)
  uri, _ = env.resolve!(input[:filename], accept: map_type)
  map = env.load(uri)
  asset.metadata.merge(
    data: asset.source + (comment % map.digest_path),
    links: asset.links + [asset.uri, map.uri]
  )
end