class Webpacker::Compiler

def webpack_env
  return env unless defined?(ActionController::Base)
  env.merge("WEBPACKER_ASSET_HOST"        => ENV.fetch("WEBPACKER_ASSET_HOST", ActionController::Base.helpers.compute_asset_host),
            "WEBPACKER_RELATIVE_URL_ROOT" => ENV.fetch("WEBPACKER_RELATIVE_URL_ROOT", ActionController::Base.relative_url_root))
end