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 = []
  find(*args) do |asset|
    files[asset.digest_path] = {
      'logical_path' => asset.logical_path,
      'mtime'        => asset.mtime.iso8601,
      'size'         => asset.bytesize,
      'digest'       => asset.hexdigest,
      # Deprecated: Remove beta integrity attribute in next release.
      # Callers should DigestUtils.hexdigest_integrity_uri to compute the
      # digest themselves.
      'integrity'    => DigestUtils.hexdigest_integrity_uri(asset.hexdigest)
    }
    assets[asset.logical_path] = asset.digest_path
    if alias_logical_path = self.class.compute_alias_logical_path(asset.logical_path)
      assets[alias_logical_path] = asset.digest_path
    end
    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 << asset.filename
  end
  save
  filenames
end