When I discovered Testing it literally changed my coding and developer experience forever. Having a high test coverage just makes your programming easier and more stable, and when you come to the release you can with much more confidence.

Mocha quickly become the test framework that I use for all Javascript based projects both on the front end and node. Mocha has a good community with tools like Chai BDD/TDD assertion library and Istanbul Code coverage tool. Mocha also integrates well with common build systems like Grunt.