Node.js unit testing [closed]
I ended up using Nodeunit and am really happy with it.
I was using Expresso originally, but the fact that it runs tests in parallel caused a few problems. (For example, using database fixtures doesn't work well in this situation.)
I was also looking for a decent test framework for node and found Mocha. It is the official successor to Expresso and seems very mature.
It allows to plug-in different assertion libraries, it offers reporters for code coverage and other things (you can plug-in your own). It can run synchronously or asynchronously and it has a concise API.
I will give it a try and report back...
EDIT:
After an incredible amount of time dedicated to other projects I finally came back to a JavaScript project and had time to play around with mocha. I can seriously recommend using it. The tests read very nicely, integration with Gulp.js is great and tests run very fast. I was able to setup automatic standalone as well as in-browser (Browserify) test runs and corresponding code coverage reports in about half a day (most of the time spent on understanding how to use Browserify from Gulp.js). To me, Mocha seems a very good choice for a testing framework.
UPDATE:
I am still very convinced about Mocha. Integration with Chai allows to plugin different assertion styles. You can checkout a working setup in this GitHub project. I am using it with karma now, integrating code coverage report, automatic watchers and good integration with IntelliJ IDEA.
Personally I've stuck with Expresso, but there are a bunch of different frameworks out there, accommodating most testing styles.
Joyent has an extensive list; give that a go.
I've personally only used the assert module, but I also find myself wanting more. I've looked through many Node.js modules and popular unit testing frameworks are Nodeunit and should (which is made by the same guy as Espresso (maybe an updated name?)
Vows also looks promising.