Comment by flohofwoe

In VSCode extensions this is trivial, this is how you create the 'executable':

https://github.com/floooh/vscode-kcide/blob/main/src/wasi.ts

...and this is how you run it:

https://github.com/floooh/vscode-kcide/blob/2dfc621aade4a2be...

The asmx.wasm file is a vanilla POSIX cmdline tool which loads and saves files via fopen/fread/frwrite/fclose, and the tool has been compiled with the WASI SDK: https://github.com/WebAssembly/wasi-sdk

The resulting VSCode extension (https://marketplace.visualstudio.com/items?itemName=floooh.v...) then even runs in the VSCode browser version (https://vscode.dev/)

But AFAIK there's currently no easy way to get a similar easy to use WASI wrapper in browsers (it's definitely possible though because the VSCode browser version does it - VSCode basically has a filesystem abstraction which works for native filesystems as well as virtualized web filesystems like github repositories).