inspec/lib/bundles/inspec-init/renderer.rb

require 'fileutils'
require 'erb'

module Init
  class Renderer
    # Creates a renderer able to render the given template type
    # 1. iterate over all files
    # 2. read content in erb
    # 3. write to full_destination_root_path

    attr_reader :overwrite_mode, :ui
    def initialize(cli_ui, cli_options = {})
      @ui = cli_ui
      @overwrite_mode = cli_options['overwrite']
    end

    # rubocop: disable Metrics/AbcSize
    def render_with_values(template_type, template_values = {})
      # look for template directory
      base_dir = File.join(File.dirname(__FILE__), 'templates', template_type)
      # prepare glob for all subdirectories and files
      template_glob = File.join(base_dir, '**', '{*,.*}')
      # Use the name attribute to define the path to the profile.
      profile_path = template_values[:name]
      # Use slashes (\, /) to split up the name into an Array then use the last entry
      # to reset the name of the profile.
      template_values[:name] = template_values[:name].split(%r{\\|\/}).last
      # Generate the full full_destination_root_path path on disk
      full_destination_root_path = Pathname.new(Dir.pwd).join(profile_path)
      ui.plain_text "Create new #{template_type} at #{ui.mark_text(full_destination_root_path)}"

      # check that the directory does not exist
      if File.exist?(full_destination_root_path) && !overwrite_mode
        ui.plain_text "#{ui.mark_text(full_destination_root_path)} exists already, use --overwrite"
        ui.exit(1)
      end

      # ensure that full_destination_root_path directory is available
      FileUtils.mkdir_p(full_destination_root_path)

      # iterate over files and write to full_destination_root_path
      Dir.glob(template_glob) do |file|
        relative_destination_item_path = Pathname.new(file).relative_path_from(Pathname.new(base_dir))
        full_destination_item_path = Pathname.new(full_destination_root_path).join(relative_destination_item_path)
        if File.directory?(file)
          ui.li "Create directory #{ui.mark_text(relative_destination_item_path)}"
          FileUtils.mkdir_p(full_destination_item_path)
        elsif File.file?(file)
          ui.li "Create file #{ui.mark_text(relative_destination_item_path)}"
          # read & render content
          content = render(File.read(file), template_values)
          # write file content
          File.write(full_destination_item_path, content)
        else
          ui.plain_text "Ignore #{file}, because its not an file or directoy"
        end
      end
    end
    # rubocop: enable Metrics/AbcSize

    # This is a render helper to bind hash values to a ERB template
    # ERB provides result_with_hash in ruby 2.5.0+, which does exactly this
    def render(template_content, hash)
      # create a new binding class
      cls = Class.new do
        hash.each do |key, value|
          define_method key.to_sym do
            value
          end
        end
        # expose binding
        define_method :bind do
          binding
        end
      end
      ERB.new(template_content).result(cls.new.bind)
    end
  end
end