Great tool, perfectly fits to the node.js ecosystem, lightweight and fast.

However in case you use co-mocha[1] to test your generators, istanbul won't work properly, the generators in the reports are shown as uncovered. Therefore I made a mocha fork[2] and directly applied the changes from co-mocha to the source (instead of monkey patching); it solved the problem.

[1] https://github.com/blakeembrey/co-mocha [2] https://github.com/tfitos/mocha