How to configure code coverage with mocha

I am using the Cloud9 IDE from AWS. I have npm-installed and correctly run my mocha test suites (“npm test”) However, I would like to be able to get code coverage statistics.

I used “Go” | “opencoverageview” to open the “Code Coverage” tab. However, all that it displays is the “All Tests” option in the filter. How do I configure cloud9 to use mocha, and see my tests? My tests use the filename pattern *.spec.js, does that need to be configured somewhere?

Thanks for any pointers!
Joel Stevick