chai
BDD / TDD assertion framework for node.js
...Plugins extend Chai's assertions to new contexts such as vendor integration & object construction. Developers can build their own plugins to share with community or use the plugin pattern to DRY up existing tests. You can also use it within the browser; install via npm and use the chai.js file found within the download. Browse our growing directory of custom plugins & vendor integrations to find the best tool for your needs. Chai has an extensive utility belt for plugin developers. Learn how to build your plugins & share.