JavaScript Articles
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Future-proofing Firefox’s JavaScript Debugger Implementation
Optimizing the integration of Firefox Developer Tools with the SpiderMonkey JavaScript engine has resulted in many benefits, including the new asynchronous call stack tracking now available in Firefox Developer Edition. In this post you can learn how that was done, down to detailed changes to memory management.
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Firefox 73 is upon us
Today we’ve released Firefox 73, with useful additions that include CSS and JavaScript updates, and numerous DevTools improvements. We’ve added to CSS logical properties, pushed performance forward in the Console and the Debugger, and improved the WebSocket inspector. Thanks to all for the ongoing DevTools feedback.
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Firefox 72 — our first song of 2020
Though we are moving to a more frequent four-week browser release cycle, the Firefox 72 release is feature-rich and full of goodies. It includes many requested DevTools' updates and improvements. We also introduce Shadow Parts and the CSS Motion Path, and useful new JavaScript features. Plus, Picture-in-picture for video is now enabled for Mac and Linux users too!
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Firefox’s New WebSocket Inspector
The Firefox DevTools team and our contributors were hard at work over the summer, getting Firefox 70 jam-packed with improvements. We are especially excited about our new WebSocket inspection feature. To use the inspector now, download Firefox Developer Edition, and open the DevTools’ Network panel to find the Messages tab. Then, keep reading to learn more about WebSockets and the tricks that the new panel has up its sleeve.
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Video Shorts from Mozilla Developer
Today we’re launching a new video channel, with a selection of shorts to kick things off. Get started with an intro to Dark Mode on the web, by Deja Hodge. Then, Jen Simmons shows us how to access a handy third-panel in the Firefox Developer Tools. Miriam Suzanne has a video all about the
::markerpseudo-element and list counters. No matter your experience level or job description, we’re all working together towards the future health of the web, and Mozilla is here to help. -
Debugging TypeScript in Firefox DevTools
Firefox Debugger has evolved into a fast and reliable tool chain over the past several months and it’s now supporting many cool features. Though it's primarily used to debug JavaScript, did you know that you can also use Firefox to debug your TypeScript applications? Jan 'Honza' Odvarko walks through some real world examples.
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Firefox 69 — a tale of Resize Observer, microtasks, CSS, and DevTools
For our latest excellent adventure, we’ve gone and cooked up a new Firefox release. Version 69 features a number of great new additions including JavaScript public instance fields, the Resize Observer and Microtask APIs, CSS logical overflow properties (e.g. overflow-block) and @supports for selectors.
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The Baseline Interpreter: a faster JS interpreter in Firefox 70
Modern web applications load and execute a lot more JavaScript code than they did just a few years ago. While JIT (just-in-time) compilers have been very successful in making JavaScript performant, we needed a better solution. We’ve added a new, generated JavaScript bytecode interpreter to the JavaScript engine in Firefox 70. Instead of writing a new interpreter from scratch, we found a way to do this by sharing most code with our existing Baseline JIT. Meet the new Baseline Interpreter.
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Firefox 68: BigInts, Contrast Checks, and the QuantumBar
Firefox 68 is available today, sporting support for big integers, whole-page contrast checks checks for accessibility, and a completely new implementation of a core Firefox feature: the ever-awesome URL bar. Dan Callahan also reports on updated CSS scroll-snapping and other features, DOM API updates, next steps in the WebRender implementation, and more.
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JavaScript and evidence-based language design
In what ways can empirical evidence be used in the design of a language like JavaScript? At TC39, as stewards of the JavaScript specification, how do we answer questions about the design of JavaScript and help make it accessible to the thousands of new coders who join the industry each year? To answer this we need to experiment, and I need your help.
