Convention for SVN and plugins

My question is regarding plugin development in Rails. I developed a
very simple plugin. I created a temporary app specifically to
development the plugin. It seems a good idea to keep the test app and
plugin code together for futher development. So, what is the current
convention for managing a plugin code in a SVN repository?? I want to
be able to install the plugin using the script/plugin install command,
etc.

Thanks,

Resident M.