module ActiveJob::QueueAdapter::ClassMethods

def load_adapter(name)
  "ActiveJob::QueueAdapters::#{name.to_s.camelize}Adapter".constantize
end

def queue_adapter=(name_or_adapter)
  @@queue_adapter = \
    case name_or_adapter
    when :test
      ActiveJob::QueueAdapters::TestAdapter.new
    when Symbol, String
      load_adapter(name_or_adapter)
    when Class
      name_or_adapter
    end
end