diff

# File railties/lib/rails/commands/credentials/credentials_command.rb, line 60
      def diff(content_path = nil)
        if @content_path = content_path
          extract_environment_option_from_argument(default_environment: extract_environment_from_path(content_path))
          require_application!

          say credentials.read.presence || credentials.content_path.read
        else
          require_application!
          disenroll_project_from_credentials_diffing if options[:disenroll]
          enroll_project_in_credentials_diffing if options[:enroll]
        end
      rescue ActiveSupport::MessageEncryptor::InvalidMessage
        say credentials.content_path.read
      end