Shared Resources Extensions
To create your own Shared Resource Extensions, you define a module with the methods in the shared/extensions folder.  Here’s a simple example:
shared/extensions/sqs_extension.rb
module SqsExtension
  def sqs_queue(logical_id, props = {})
    defaults = {message_retention_period: 120}
    props = defaults.merge(props)
    resource(logical_id, "AWS::SQS::Queue", props)
    output(logical_id)
  end
end
After the module is defined, you can use the method in your Shared Resource like so:
shared/resources/list.rb
class List < Jets::Stack
  sqs_queue(:fastpass, receive_message_wait_time_seconds: 20)
end
The code above creates an SQS Queue with a message_retention_period of 120 seconds and a receive_message_wait_time_seconds of 20 seconds.  By creating your own resource extensions, you can shorten your code and remove duplication.
Note: The sqs_queue is an example and is actually already implemented by Jets. We’re using it for demonstrative purposes.