ViewComponent Lookbook preview generator

component_preview_generator.rb

class ComponentPreviewGenerator < Rails::Generators::NamedBase
  source_root File.expand_path("templates", __dir__)
  class_option :preview_names, type: :array, default: ["default"], desc: "A list of different previews to add to the configuration"
  class_option :grouped, type: :string, default: 'true', desc: "Should the previews be grouped into one view?"
  class_option :erb_files, type: :string, default: 'true', desc: "Should the previews use erb templates? If false, preview methods must render the component."

  desc "Create a Lookbook preview for a ViewComponent"
  def create_lookbook_preview
    template "view_component_preview.rb", "spec/components/previews/#{file_path}_preview.rb"
    if options[:erb_files] == 'true'
      options[:preview_names].each do |preview_name|
        create_file "spec/components/previews/#{file_path}_preview/#{preview_name}.html.erb"
      end
    end
  end
end

USAGE

Description:
    Make ViewComponent previews for Lookbook

Example:
    bin/rails generate component_preview my_new_component

    This will create:
        spec/components/previews/my_new_component_preview.rb
        spec/components/previews/my_new_component_preview/default.html.erb

Options:
    bin/rails generate component_preview --help

view_component_preview.rb.tt

class <%= class_name %>Preview < ViewComponent::Preview
  layout "view_component_preview"

  <%= options[:grouped] == 'true' ? '# @!group' : '' %>
  <% options[:preview_names].each do |preview_name| %>
  def <%= preview_name %>
  end
  <% end %>
  <%= options[:grouped] == 'true' ? '# @!endgroup' : '' %>
end

lib/generators/component_preview/USAGE 
lib/generators/component_preview/component_preview_generator.rb 
lib/generators/component_preview/templates/view_component_preview.rb.tt