class AbstractController::Helpers::MissingHelperError

def initialize(error, path)
  @error = error
  @path  = "helpers/#{path}.rb"
  set_backtrace error.backtrace
  if /^#{path}(\.rb)?$/.match?(error.path)
    super("Missing helper file helpers/%s.rb" % path)
  else
    raise error
  end
end