gem

# File railties/lib/rails/generators/actions.rb, line 22
      def gem(*args)
        options = args.extract_options!
        name, *versions = args

        # Set the message to be shown in logs. Uses the git repo if one is given,
        # otherwise use name (version).
        parts, message = [ quote(name) ], name.dup

        # Output a comment above the gem declaration.
        comment = options.delete(:comment)

        if versions = versions.any? ? versions : options.delete(:version)
          _versions = Array(versions)
          _versions.each do |version|
            parts << quote(version)
          end
          message << " (#{_versions.join(", ")})"
        end
        message = options[:git] if options[:git]

        log :gemfile, message

        parts << quote(options) unless options.empty?

        in_root do
          str = []
          if comment
            comment.each_line do |comment_line|
              str << indentation
              str << "# #{comment_line}"
            end
            str << "\n"
          end
          str << indentation
          str << "gem #{parts.join(", ")}"
          append_file_with_newline "Gemfile", str.join, verbose: false
        end
      end