Web Interop 2024

The article The web just gets better with Interop 2024 by Jen Simmons (Webkit Blog) writes,

“The Interop project aims to improve interoperability by encouraging browser engine teams to look deeper into specific focus areas. Now, for a third year, Apple, Bocoup, Google, Igalia, Microsoft, and Mozilla pooled our collective expertise and selected a specific subset of automated tests for 2024.

“Some of the technologies chosen have been around for a long time. Other areas are brand new. By selecting some of the highest priority features that developers have avoided for years because of their bugs, we can get them to a place where they can finally be relied on.”

When we complain about features that remain unimplemented in browsers, we also have to acknowledge that there’s only so much you can do with a given team. There are problems that are technically easier to solve than others. When we complain, we’re actually more concerned about the prioritization of issues. We want to be able to influence what gets fixed when, rather than just having to passively hope that the manufacturer eventually gets around to it.

That where the Web Platform Tests come in. The Interop 2024 project follows on iterations from 2023, 2022, and 2021, when it all started.

Last year was a banner year. For CSS “Subgrid, Container Queries, :has(), Motion Path, CSS Math Functions, inert and @property are now supported in every modern browser.” For JavaScript, we got “Improved Web APIs include Offscreen Canvas, Modules in Web Workers, Import Maps, Import Assertions, and JavaScript Modules” across all modern browsers.

These are all super-important features. E.g., Import Assertions for JSON import and Modules in Web Workers, which allows modern and modular programming, making it much easier to offload work, as one would with code running directly on modern operating systems.

What’s on the schedule for 2024?

• Although there was a lot of progress made on CSS nesting last year, it’s back on the radar this year to finalize the implementations.
• @property will similarly be more polished, as the percentage support is still quite low in many browsers.
• It’s great to see accessibility improvements for many of these features—like how sub-grids or display: contents affect element order—as this means that we will get sites that are automatically accessible, as long as we build our sites logically.
• Improvements to IndexedDB will make it easier to write powerful local-first applications (even though something like Automerge might be a better fit for apps offering concurrent or collaborative editing).
• Browser- and standards-level support for popover with anchors is long overdue, as making usable tooltips and popups is an area fraught with custom code and half-baked solutions. It’s nice to see this become an area where you’ll no longer need custom JavaScript.
• Relative Color Syntax continues the excellent trend of allowing us to write CSS without the support of a CSS preprocessor. With relative colors, dark/light theming support, CSS nesting, and CSS variables, I can’t think of a reason I would use a CSS preprocessor anymore. I know some people have used them for so much more, but I’ve not done so, so my needs are already covered, even without this extension that allows conversion between colorspaces.
• @starting-style will fill a gap in CSS that finally allows sites to indicate how an element will transition from or to display: none.

See the original article for much more detail.