fastdom VS proposal-import-attributes

Now, every time we read `offsetHeight`, the browser sees that it has a scheduled DOM modification to apply, so it has to apply that first, before it can return a correct value.

This is the reason that libraries like fastdom (https://github.com/wilsonpage/fastdom) exist - they help ensure that, in a given tick, all the reads happen first, followed by all the writes.

That said, I suspect even if you add a write followed by a read to your `while(1)` experiment, it still won't actually render anything, because painting is a separate phase of the rendering process, which always happens asynchronously. But that might not be true, and I'm on mobile and can't test it myself.

batching your writes & reads to the DOM (via FastDOM or a virtual DOM implementation).

For more information on how and why this works, and a more robust and complete implementation, check out the FastDom library: https://github.com/wilsonpage/fastdom - note that you might not need this particular optimization if you're using a rendering framework, which should already be doing these sorts of optimisations for you.

Bun introduces the idea of Macros into JavaScript. Macros are a new paradigm that allows optimizations ahead of time just by adding an import attribute.

TypeScript v5.3 builds on its JavaScript foundation by adding import attributes with the usual type safety and tooling benefits inherent to the language. You can follow the TypeScript proposal for import attributes on GitHub.

Yup, in vanilla that's fine, but I'm not sure whether bundlers etc are able to understand import assertions yet, as the spec is still being finalised - for example: the 'assert' keyword has now been officially changed to 'with', but only 'assert' is implemented anywhere at the moment.

Things like HTML (and JSON) imports in ES modules, among other things, have been waiting on some safety signalling mechanics currently named "Import Attributes". Import Attributes are currently in Stage 3 [0].

The basic security story is that browsers never care about file extensions, they care about MIME types. A developer might add an import to a third-party HTML or JSON file somewhere and expect one "safe" behavior, but the third-party could just return a MIME type of "text/javascript" and inject an entire script and the browser is supposed to respect that MIME type.

To keep things safe, browsers want a way to signal that an import is supposed to JSON (or HTML or CSS) rather than JS and error if it gets back something "wrong" from a server request. That's one of the proposed uses for Import Attributes to suggest expected MIME types for non-JS modules in ES module imports.

Unfortunately, there are other proposed uses for Import Attributes (things like including hashes for integrity checks) and so there have been quite a few revisions (and multiple names) for Import Attributes trying to best support as many of the proposed uses as possible, and that has slowed progress on it a lot more than some people would wish.

[0] https://github.com/tc39/proposal-import-attributes

This was an idea that I came up with when thinking about how to handle import styles from './styles.css' with { type: 'css' } in @shgysk8zer0/rollup-import. Import assertions / import attributes are now back to stage 3, but only JSON is actually progressing. So I decided to wait until there's a stable spec.

None of these examples will actually work in a browser, because they are non-standard. Some of you might have correctly spotted that a browser standard exists for two of the imports pointed out in the example, namely the Import Attributes proposal (previously known as Import Assertions), but these imports in their current shape will not work natively in a browser. Many of these non-standard imports exist for good reason; they are very convenient.

import attribute: Import Assertions re-adanced to Stage-3. Proposal for syntax to import ES modules with assertions