May I introduce to you: preparsed Javascript sent over the wire: https://github.com/binast/binjs-ref

Isn’t that just an AST? That still has to be parsed and compiled. It just makes parsing a bit faster.

From the README:

> Current advanced prototypes already show JS parsing improvements of 30%-50% on all the most common frameworks, just by changing the format, and we believe that we can increase this improvement much further.

30% is more than a bit :).

I’ve worked professionally on pre-parsing and 30% is not a great result.

And it doesn’t help the time spent on compiling, so it’s saved not a lot of not a lot. Doesn’t really solve the problem.

True, but (unfortunately) it's hardly an outlier in today's ecosystem.

Try importing `flutter/animation` — footprint goes WAY off the deep end. `animation.ddc.js` is 4.4MB alone (unminified), never mind the rest of the runtime AND userland application code.

You can see this in the flutter_web/examples/gallery example. [`webdev build` failed for me in examples/gallery, so I'd love to see what a successfully minified version of that example looks like — I'm currently deeply skeptical.]

Compared to React/Vue/Angular and friends, this appears to be a monstrous outlier.

DDC stands for Dart Development Compiler. It is a fast modular compiler that you use for quick edit&refresh development in the browser. It does not do any global optimizations, unlike dart2js - which is what you use for deployment.

If you write something like:

    import 'package:flutter_web/animations.dart';

    void main() => print('Hello, World!');

DDC would faithfully compile animations.dart as whole and ship that to your browser.

dart2js would include 0 bytes of code from animations.dart into the output.

> `webdev build` failed for me in examples/gallery

Maybe file a bug?

Here is what I get for Gallery:

    ╭─~/s/f/f/e/gallery ⟨master ⟩ ⟨9s449ms⟩
    ╰─» flutter packages pub global run webdev build
    ...
    Compiled 18,344,245 characters Dart to 1,914,077 characters JavaScript in 27.9 seconds

If I gzip the output I get around 500k.

Gallery uses a lot of Flutter so this is in some sense upper boundary for framework overhead.

Also it is still early days - I can clearly see this pushed down.

DDC is not at all a representation of the final size of the code, as it doesn't run any kind of tree shaking, minification or optimization, and the animation library has a lot of things that you will definitely not import.

And here I am freaking about an uncompressed js payload of 300k for an entire app... 4+MB just feels crazy.

Yes, but it’s more or less in line with current single page apps. In fact, quite possibly a bit smaller.

not sure how many "Hello, World" SPAs would add up to that.

The point is, real world apps have a bit more complexity than "hello, world", and the runtime cost doesn't matter as much as the app grows in size.