Writing JavaScript modules that can be seamlessly included in client-side as well as server-side applications, and providing Jasmine test suites which allow to test these modules in a browser environment as well as a Node.js environment is possible without any dirty workarounds by writing these modules using the AMD pattern, and then using the amdefine package to make them available to Node.js.
Read more at http://manuel.kiessling.net/2012/03/30/true-universal-javascript-modules-with-write-once-run-anywhere-jasmine-specs/