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Introduction Accessing paint metrics from JavaScript Reporting paint timing metrics to a server Viewing paint metrics in the Chrome DevTools Browser Implementations Traditionally, front-end performance focused primarily on page load times as an important performance metric. Commercial web performance dashboards would show granular level performance metrics for back-end aspects, like database lookup times, template compilation, server response times, etc.

Automating browsers provide many benefits including faster execution of repetitive tasks, ability to parallelise workloads and improved test coverage for your website. Google recently announced Puppeteer, a new tool to assist with Chrome browser automation.

For a web framework to be effective, it should offer you more than just functionality. It doesn’t matter how much hard work you put into your application if it breaks when people use it.

On the modern web platform, many interesting features appear which enable new functionality which were not previously possible, for example, Web Bluetooth, Background Sync & Web VR. For new features in JavaScript specifically, many are just syntactic sugar for things you could already do in an alternative way, like template literals, arrow functions & the spread operator.

Intern is an incredibly powerful and feature-rich approach to all types of JavaScript and TypeScript testing. Intern 4 is a major update refactored in TypeScript and with much improved support for modern language features and support for ESM as well as bundlers like webpack.