happy-dom is a lightweight and fast DOM implementation for testing and server-side rendering in JavaScript applications. It provides a simple API to manipulate the DOM and is particularly useful for testing libraries and frameworks that rely on DOM manipulation. While happy-dom is a great choice for DOM simulation, there are several alternatives in the ecosystem that serve similar purposes. Here are a few notable options:

• cheerio is a fast, flexible, and lean implementation of core jQuery designed specifically for the server. It allows developers to manipulate and traverse HTML and XML documents using a jQuery-like syntax. Cheerio is particularly useful for web scraping and server-side HTML manipulation, making it a popular choice for projects that require parsing and manipulating HTML without the overhead of a full browser environment.
• enzyme is a testing utility for React that makes it easier to assert, manipulate, and traverse your React components' output. While it is primarily focused on React components, it provides a robust API for simulating events and interacting with the component's lifecycle. Enzyme is a great choice for testing React applications, especially when you need to perform shallow rendering or full DOM rendering.
• jsdom is a JavaScript implementation of the DOM and HTML standards, providing a simulated browser environment for Node.js. It allows developers to run tests that require a DOM without needing a real browser. jsdom is widely used in testing frameworks and libraries, making it a versatile choice for applications that need a comprehensive DOM simulation.
• playwright is a powerful browser automation library that allows developers to write scripts for testing web applications across different browsers. It provides a high-level API for interacting with web pages, making it suitable for end-to-end testing. Playwright is ideal for scenarios where you need to test the behavior of your application in real browser environments, including handling complex user interactions and network conditions.
• puppeteer is another popular library for browser automation, specifically designed for controlling headless Chrome or Chromium. It provides a simple API for performing tasks such as taking screenshots, generating PDFs, and scraping web pages. Puppeteer is particularly useful for tasks that require a real browser environment, making it a great choice for testing and automation.

To see how happy-dom compares with cheerio, enzyme, jsdom, playwright, and puppeteer, check out the comparison: Comparing cheerio vs enzyme vs happy-dom vs jsdom vs playwright vs puppeteer.