Annotate rails models on db:migrate

annotate_on_migration.rake

if Rails.env.development?
  def after_task(task_name, &new_task)
    old_task = Rake.application.instance_variable_get('@tasks').delete(task_name.to_s)
    desc old_task.full_comment
    task task_name do
      old_task.invoke
      new_task.call
    end
  end

  after_task "db:migrate" do
    system("bundle exec annotate -e tests,fixtures -p after | grep -v 'Nothing annotated.'") || exit(1)
  end
end