Tiny JavaScript library that simplifies subclassing and inheriting from Error while keeping the correct name and stack. Also supports constructing from an object of properties. Saves you from boilerplate.

An assertion library for JavaScript and Node.js with a friendly BDD syntax (awesome.must.be.true()). It ships with many expressive matchers and is test runner and framework agnostic. Follows RFC 2119 with its use of MUST. Good stuff and well tested.

Intercept and mock outgoing Node.js network TCP connections and HTTP requests for testing. Intercepts and gives you a Net.Socket, Http.IncomingMessage and Http.ServerResponse to test and respond with. Super useful when testing code that hits remote servers.

JavaScript Polyfill for Promise.defer. Uses the native ES6 Promise. Supports other Promises/A+ implementations.