Nock
HTTP mocking and expectations library
Grunt
Grunt: The JavaScript Task Runner
Nightwatch
UI automated testing framework based on node.js and selenium webdriver
Gulp
The streaming build system
Rulers Guides.js
Creates Photoshop-like guides and rulers interface on a web page
Blaver
A JavaScript library built on top of the Faker.JS library. It generates massive amounts of fake data in the browser and node.js.
Angular Debaser
Just a better way to test AngularJS apps.
Recoil
Recoil is an experimental state management library for React apps. It provides several capabilities that are difficult to achieve with React alone, while being compatible with the newest features of React.
Trace Kit
Attempts to create stack traces for unhandled JavaScript exceptions in all major browsers.
Headstart
An automated front-end setup
Casper JS
Navigation scripting & testing utility for PhantomJS and SlimerJS
Jasmine
DOM-less simple JavaScript testing framework
Stacktrace.js
Framework-agnostic, micro-library for getting stack traces in all web browsers
Qunit
An easy-to-use JavaScript Unit Testing framework.
Fast Check
Property based testing framework for JavaScript (like QuickCheck) written in TypeScript
Browser Sync
Keep multiple browsers & devices in sync when building websites. http://browsersync.io
Csscritic
A lightweight framework for regression testing of Cascading Style Sheets