a counter is valid but generally it makes it a mess to find out where the error is if&when the test fails... (http://visionmedia.github.com/mocha/#asynchronous-code)... In general if your curious about what can/cant the test runner do then looking at the mocha docs is a good idea... test-agent is a big wrapper around mocha to enable some extra sanboxing/app specific stuff... 

( we are using the tdd interface so where describe is we use "suite" and "it" is "test")