module Sprockets::Rails::Helper

def compute_asset_path(path, options = {})

to use the asset pipeline.
Writes over the built in ActionView::Helpers::AssetUrlHelper#compute_asset_path
def compute_asset_path(path, options = {})
  debug = options[:debug]
  if asset_path = resolve_asset_path(path, debug)
    File.join(assets_prefix || "/", legacy_debug_path(asset_path, debug))
  else
    message =  "The asset #{ path.inspect } is not present in the asset pipeline.\n"
    raise AssetNotFound, message unless unknown_asset_fallback
    if respond_to?(:public_compute_asset_path)
      message << "Falling back to an asset that may be in the public folder.\n"
      message << "This behavior is deprecated and will be removed.\n"
      message << "To bypass the asset pipeline and preserve this behavior,\n"
      message << "use the `skip_pipeline: true` option.\n"
      Sprockets::Rails.deprecator.warn(message, caller_locations)
    end
    super
  end
end