proposal-import-attributes VS stencil

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

First a disclosure: I never actually used Stencil, only played with it a bit locally in a hello-world project while writing this post.

This is my main concern too.

I don't understand why tools like this "pick a winner" with a specific framework instead of rendering to Web Components with a framework wrapper, or using something like Stencil[1] that can render to any framework.

[1] https://stenciljs.com/

I was recently able to sit down with some of the core members of Ionic, who also created Stencil a toolchain for building Design Systems and Progressive Web Apps. We talked at great length how typically companies are approaching Ionic from a Design Team and need help building components. As a developer I wanted to talk about the Web Components that are used within the Design System first. There was a decent amount of surprise, so I thought I would break down what a Design System is and why it doesn't matter which end you start with, as long as you have both your Design and Development teams working together to build your Design System.

Examples like this bug me. The React example is using a high level abstraction, the web component is directly using the API. A more accurate example would show how those React calls eventually boil down to document.createElement()

I don’t think the Web Components API was meant to be used directly all the time. You can use a framework like StencilJS:

https://stenciljs.com/

You might say that this is the same vicious cycle as JavaScript frameworks. That's wrong, because Web Components are interoperable by design. Choosing Stencil or Lit or any other library is a development convenience that has little to do with the interoperability of the resulting components.

Not sure about Vue but you can in Angular, though my experience with React components in Angular has not been pleasant. Libraries such as Stencil allow you to create native Web Componets from React components.

I guess my problem is more specific to my overall architecture. I have components that when are placed in the DOM, have props rendered on them by their parent elements. I'm using stencil to do this.