Originally, I was going to use D, but its current WASM guideline is buried under a lot of Discord threads, all while people are lazy to touch the wiki. I need to test stuff with WASM (use for scripting in applications, not browsers).
Please NO RUST!!! While I see why functional programming is useful (I even use wasmtime as my WASM engine, which is developed in Rust), but is horribly counterproductive for game development, especially if it’s opt out like in Rust.
EDIT: In the meanwhile, I’ve found AssemblyScript, which seems to be good for my usecase.
Scala-js is working on it - as its compiler design may facilitate this.
I haven’t yet tried (on todo list) and am not an expert, but bookmarked in passing:
recent github implementation, some history, following older discussion