I’ve been trying and failing for a while to apply the instructions to the web-sys examples in the yew repository. I’ll take todomvc as an example. Everything up to and including wasm-pack build is fine. The problems start at the next line:

rollup ./main.js --format iife --file ./pkg/bundle.js

Ok, there is no main.js, so maybe I should put pkg/todomvc.js? Well,

> rollup pkg/todomvc.js --file ./pkg/bundle.js

pkg/todomvc.js → ./pkg/bundle.js...
[!] Error: Unexpected character '' (Note that you need plugins to import files that are not JavaScript)
pkg/todomvc_bg.wasm (1:0)
1: asm
…

Ok, so I need to install a wasm plugin for rollup with npm install @rollup/plugin-wasm --save-dev and add a file rollup.config.js containing

import wasm from '@rollup/plugin-wasm';

export default {
  plugins: [wasm()]
};

Now I can run rollup -c rollup.config.js pkg/todomvc.js --file pkg/bundle.js. Cool. The next step is

python -m http.server 8000

(or any other server, as the tutorial notes). Running this and visiting localhost:8000 in my browser shows me the contents of the todomvc directory. Ok, not exactly what I wanted, so I run

python -m http.server 8000 --directory static

because index.html is in the static directory. This time I get a page with the title Yew • TodoMVC, which is good, but the page is entirely blank. The console shows the error message Loading failed for the <script> with source “http://localhost:8000/todomvc.js”., which makes sense to me because todomvc.js resides in pkg. Also, I am now unsure whether using rollup even accomplished anything because I haven’t interacted with bundle.js in any way.

Maybe I’m going about this very stupidly. After all, I am a complete beginner when it comes to any sort of web development.