Sites like mochajs.org

A JavaScript library documentation site for Sinon.JS, offering stubs, spies, fakes and mocks for unit tests

A JavaScript testing framework named Jest, documented on its official site, with French and English pages and community help

WebdriverIO API reference documentation for the WebdriverIO browser and mobile test automation framework's commands and protocol bindings

Babel, an open-source JavaScript compiler project with documentation, a browser REPL and a team page, converting modern JavaScript to older-compatible code

A JavaScript toolkit, gulp.js, for automating build workflows with composable streaming tasks and plugins, documented through its project website

ESLint project website: documentation, playground and team pages for ESLint, the pluggable open-source JavaScript linter

A testing framework called Vitest, powered by Vite, with documentation for writing, mocking and configuring JavaScript tests

Mongoose, an object modeling library for MongoDB in JavaScript, with documentation, changelog, news and plugin listings

A documentation site for Changesets, an open-source tool for managing package versioning and changelogs in monorepos and CI

Appium documentation: an open-source software project for UI automation of mobile, browser and desktop apps

Selenium, an open-source browser automation tool for web application testing, documented on its official project website

Yarn, a JavaScript package manager; its documentation and API reference for the @yarnpkg packages

The Rollup JavaScript module bundler's official website, with documentation, FAQs, an online REPL and browser build guides

Prettier, an opinionated code formatter for JavaScript, CSS, Markdown and other languages, with editor and CI integrations

JUnit, a open-source testing framework for Java and the JVM, with documentation, release notes and project information

A utility that automatically restarts Node.js applications when source files change, used during development

A documentation site for pytest, the Python testing framework, with a list of talks, books and tutorials about it

AVA, a GitHub repository hosting a Node.js test runner for running JavaScript unit tests concurrently

Documentation and project site for Passport.js, an authentication middleware library for Node.js applications

Stylelint, a linter for CSS and related stylesheet syntax, with documentation, changelog, contributing guide and vision pages

PHPUnit project website by Sebastian Bergmann covering the PHP testing framework, its releases, documentation, sponsors and community events

Parcel, a zero-configuration JavaScript build tool for the web, with release announcements and blog posts from its team

Vite, a frontend build tool and development server for modern web projects, documented by its core team

Node.js, an open-source cross-platform JavaScript runtime for building servers, web apps, command line tools and scripts

PostCSS, a JavaScript tool documentation site for transforming CSS with plugins such as Autoprefixer and its API reference

Rust-based open source platform of fast developer tools such as a JavaScript/TypeScript compiler, documented by its project team

xUnit.net is an open source unit testing tool for C#, F# and Visual Basic, led by project lead Brad Wilson

Modern Web: guides, documentation and open-source tools for building websites on web standards, with browser-native code and minimal tooling

Ramda, a documentation site for a practical JavaScript functional programming library and its function reference

The official website of Vue.js, the open-source JavaScript framework for building web user interfaces, with its API reference and documentation

fast-check is a property-based testing library for JavaScript and TypeScript, with documentation and blog posts by maintainer Nicolas Dubien

NgRx documentation and guides on reactive state management for Angular applications, covering the Global Store and SignalStore

Serenity/JS, a TypeScript-native framework and modular NPM packages for acceptance and end-to-end test automation with Playwright, WebdriverIO and Cucumber

Open source self-hosted dashboard for recording, parallelizing and debugging Cypress end-to-end tests, by Currents.dev

Faker, a JavaScript library documentation site for generating realistic fake test data, with API reference, guide and modules

Madeline's personal site (superchupu) with JavaScript coding notes, blog posts about her level-making projects, and the tinyglobby npm file-globbing tool

Tim Deschryver's blog on .NET, Angular, testing and agentic AI, with Belgian software engineer writing lessons learned from building software

typescript-eslint is a documentation site for the ESLint plugin and parser that lint TypeScript code, with its rules and playground

Vite, a frontend build tool and documentation site for modern web application development, with team and event pages

NativeScript, an open-source framework for building native iOS and Android apps with TypeScript, plus a showcase of community apps