Fast Check
Property based testing framework for JavaScript (like QuickCheck) written in TypeScript
6to5
Turn ES6 code into readable vanilla ES5 with source maps
Faker.js
generate massive amounts of fake data in Node.js and the browser
Stencil
A Web Component compiler for building fast, reusable UI components and Progressive Web Apps 💎 Built by the Ionic Framework team
Gulp
The streaming build system
Cypress
Fast, easy and reliable testing for anything that runs in a browser.
Quixote
CSS unit testing
Brjs
BladeRunnerJS (BRJS) is an open source development toolkit and framework for modular construction of large single-page HTML5 apps. It consists of a set of conventions, supporting tools and micro-libraries that make it easy to develop, test, deploy and maintain complex JavaScript apps.
Wire
A light, fast, flexible Javascript IOC container
Csscritic
A lightweight framework for regression testing of Cascading Style Sheets
Prettydiff
Compare code instead of text.
Thrill
Runs tests in many browsers.
Monitor.io
remote monitoring and debugging for socket.io
Headstart
An automated front-end setup
Stacktrace.js
Framework-agnostic, micro-library for getting stack traces in all web browsers
Hashgrid
A little tool that inserts a layout grid in web pages, allows you to hold it in place, and toggle between displaying it in the foreground or background.
Galen
Layout and functional testing framework for websites