module Sprockets::Engines

# => CoffeeScriptTemplate
environment.engines('.coffee')

# => {".coffee" => CoffeeScriptTemplate, ".sass" => SassTemplate, ...}
environment.engines

that extension will be returned.
If an `ext` argument is supplied, the `Engine` associated with
Returns a `Hash` of `Engine`s registered on the `Environment`.

def engines(ext = nil)
  if ext
    ext = Sprockets::Utils.normalize_extension(ext)
    @engines[ext]
  else
    @engines.dup
  end
end