module AWS::S3::Client::Validators

def validate_bucket_name!(bucket_name)
  validate!('bucket_name', bucket_name) do
    case
    when bucket_name.nil? || bucket_name == ''
      'may not be blank'
    when bucket_name !~ /^[a-z0-9._\-]+$/
      'may only contain lowercase letters, numbers, periods (.), ' +
      'underscores (_), and dashes (-)'
    when bucket_name !~ /^[a-z0-9]/
      'must start with a letter or a number'
    when !(3..255).include?(bucket_name.size)
      'must be between 3 and 255 characters long'
    when bucket_name =~ /(\d+\.){3}\d+/
      'must not be formatted like an IP address (e.g., 192.168.5.4)'
    when bucket_name =~ /\n/
      'must not contain a newline character'
    end
  end
end