For testing of the citeproc-js utility (used in Zotero and Mendeley
bibliography managers), I use the DOH test framework from the Dojo
project.  When running code in Rhino (or other standalone interpreter
such as jslibs/jshost), It provides a command-line test environment,
similar to that used in Python and other scripting languages.  For
citeproc-js development I wanted to have a rapid command-line testing
cycle, and DOH has worked out quite well for that.

  http://dojotoolkit.org/reference-guide/util/doh.html

  http://www.sitepen.com/blog/2008/04/15/unit-testing-custom-code-with-the-dojo-objective-harness/

  https://bitbucket.org/fbennett/citeproc-js/src

Frank Bennett