class Sprockets::Manifest

def compile(*args)


compile("application.js")

also inserted into the manifest file.
`application-2e8e9a7c6b0aafa0c9bdeec90ea30213.js`. An entry is
fingerprinted filename like
Compile and write asset to directory. The asset is written to a 
def compile(*args)
  unless environment
    raise Error, "manifest requires environment for compilation"
  end
  filenames = []
  filter_logical_paths(*args).each do |_, filename|
    find_assets(filename) do |asset|
      files[asset.digest_path] = {
        'logical_path' => asset.logical_path,
        'mtime'        => asset.mtime.iso8601,
        'size'         => asset.bytesize,
        'digest'       => asset.digest
      }
      assets[asset.logical_path] = asset.digest_path
      target = File.join(dir, asset.digest_path)
      if File.exist?(target)
        logger.debug "Skipping #{target}, already exists"
      else
        logger.info "Writing #{target}"
        asset.write_to target
      end
      filenames << filename
    end
  end
  save
  filenames
end