rack-sprocketize

https://github.com/petebrowne/rack-sprocketize

Rack::Sprocketize is a piece of Rack Middleware which uses Sprockets to concatenate javascript files and then optionally compresses them. In a development environment, the files will be sprocketized on each request if there have been changes to the source files. In a production environment, the files will only be sprocketized one time, and only if there have been changes. Also, in a production environment, the files will be compressed by whichever javascript compressor is available.