Development server

[MarcAntoine-Arnaud]

Motivation

Wasm-bindgen provide all requirements to generate Wasm application. Including the startup with the #[wasm_bindgen(start)] attribute.
It miss a very little portion of code to:

• start a server
• (re-)build the wasm application

Today, it requires an external tool, hot reloading is not provided etc.
It can be with WebPack:
Paint example
Or using the wasm-bindgen-cli
GFX example

One of the paint/complex work is to manage cross target libraries.
For example the Quad example from GFX is a main as it can run on all platforms.
But the same code can also run for Web with WebAssembly.
I have tried to manage that in that issue: gfx-rs/gfx#3475
It works using 2 Cargo manifests, requires to duplicate dependencies and do some tricks.

Proposed Solution

Improve the CLI crate to add a mode to serve the application.
maybe to provide a command like:
wasm-bindgen --server
Or maybe add a server target.

[alexcrichton]

Thanks for the report! This is something I'd be happy to help design and take a PR for, but I don't really know of a great design or how it would fit into wasm-bindgen myself. There's already basically a server for wasm-bindgen-test so that can probably be reused.

This would be a great feature to have though!

[MarcAntoine-Arnaud]

Hello,

I wanna to work on it, @alexcrichton do you have some advices ?
Do you have idea what I need to check first ?

For me it means:

• call cargo build command - maybe with watch option
• call wasm-bindgen-cli
• serve over HTTP (I plan to use https://crates.io/crates/https)

Thank you,
Marc-Antoine

[alexcrichton]

Yeah that's the rough shape of ideally what this would look like. I think it'd be good though to make a proposal for the interface for this and how it's expected to be used, though.