class Bundler::Dsl

def validate_keys(command, opts, valid_keys)
  invalid_keys = opts.keys - valid_keys
  if invalid_keys.any?
    message = "You passed #{invalid_keys.map {|k| ":" + k }.join(", ")} "
    message << if invalid_keys.size > 1
                 "as options for #{command}, but they are invalid."
               else
                 "as an option for #{command}, but it is invalid."
               end
    message << " Valid options are: #{valid_keys.join(", ")}"
    raise InvalidOption, message
  end
end