Spawn local

[richard-uk1]

This is a very simple implementation of spawn_local, a function that spawns a rust future using the javascript promise infrastructure as the executor.

[lcnr]

Is there a reason why only a F: Future<Item = (), Error = ()> is allowed?
I would personally prefer

pub fn spawn_local(future: impl Future + 'static) {
    future_to_promise(
        future
            .map(|_| JsValue::undefined())
            .map_err(|_| JsValue::undefined()),
    );
}

[richard-uk1]

I changed this to what you suggest :)

[Pauan]

@lcnr It is standard practice to require (). See tokio::run and stdweb::spawn_local.

The reason this is done is to prevent mistakes, and also to force the user to handle errors (rather than silently ignoring them, which is very bad!)

[richard-uk1]

Happy to do it either way. Maybe we should match other libraries though @lcnr. You can always make your own wrapper

pub fn spawn_local(future: impl Future + 'static) {
    wasm_bindgen_futures::spawn_local(
        future.map(|_| ()).map_err(|_| ())
    )
}

[lcnr]

I thought about it and agree with @Pauan .

[richard-uk1]

woop consensus.

[richard-uk1]

Are the docs good enough? It might be that the module documentation needs to be changed.

[alexcrichton]

Thanks @derekdreery!