Add custom models to Annotate Gem

config annotate.yml

Foo:
  - interactions/foo/
  - interactions/user/bar/
  - interactions/baz.rb
Bar:
  - interactions/bar/
  - interactions/user/bar/

config initializers annotate.rb

# For 'annotate' gem version 2.7.4

module AnnotateModels

  class << self
    def annotate(klass, file, header, options = {})
      begin
        klass.reset_column_information
        info = get_schema_info(klass, header, options)
        model_name = klass.name.underscore
        table_name = klass.table_name
        model_file_name = File.join(file)
        annotated = []

        if annotate_one_file(model_file_name, info, :position_in_class, options_with_position(options, :position_in_class))
          annotated << model_file_name
        end

        # Begin Custom loading
        options[:custom_dir] = YAML.load(File.read(Rails.root.join("config","annotate.yml")))
        custom_directories = options[:custom_dir][klass.to_s] || []
        custom_directories.each do |custom_directory|

          dir = Rails.root.join("app", custom_directory)

          if File.file?(dir)
            found_files = [dir]
          elsif File.directory?(dir)
            found_files = Dir[Rails.root.join("app", custom_directory)+"*.rb"]
          else
            found_files = []
          end

          found_files.each do |found_file_name|
            if annotate_one_file(found_file_name, info, :position_in_class, options_with_position(options, :position_in_class))
              annotated << found_file_name
            end
          end
        end
        # End Custom Loading

        matched_types(options).each do |key|
          exclusion_key = "exclude_#{key.pluralize}".to_sym
          position_key = "position_in_#{key}".to_sym

          # Same options for active_admin models
          if key == 'admin'
            exclusion_key = 'exclude_class'.to_sym
            position_key = 'position_in_class'.to_sym
          end

          next if options[exclusion_key]
          get_patterns(key)
            .map { |f| resolve_filename(f, model_name, table_name) }
            .each do |f|
              if annotate_one_file(f, info, position_key, options_with_position(options, position_key))
                annotated << f
              end
            end
        end
      rescue StandardError => e
        $stderr.puts "Unable to annotate #{file}: #{e.message}"
        $stderr.puts "\t" + e.backtrace.join("\n\t") if options[:trace]
      end

      annotated
    end
  end
end

This allows for custom loading of extra directories, in this case I am using the ActiveInteraction gem and custom load the files to annotate.

I added a file/directory check to allow for individual files to be added.