Converting JsUint8Array to Vec<u8>

[mlafeldt]

Hey,

I want to use Uint8Array. Converting a string to Uint8Array seems easy enough:

fn from_string(_this: &JsValue, args: &[JsValue], ctx: &mut Context<'_>) -> JsResult<JsValue> {
    let str: String = args.get_or_undefined(0).try_js_into(ctx)?;
    let arr = JsUint8Array::from_iter(str.bytes(), ctx)?;
    Ok(arr.into())
}

But how can I do the opposite and get access to the underlying Vec<u8>:

fn to_string(_this: &JsValue, args: &[JsValue], ctx: &mut Context<'_>) -> JsResult<JsValue> {
    let arr: JsUint8Array = args.get_or_undefined(0).try_js_into(ctx)?;
    // ???
}

Thanks!

[mlafeldt]

Also fine if it's just not possible right now.

[jedel1043]

I think it should be possible to use JsArrayBuffer::take for this. Though, note that this will detach the buffer backing the JsUint8Array.
Example:

let str: String = args.get_or_undefined(0).try_js_into(ctx)?;
let arr = JsUint8Array::from_iter(str.bytes(), ctx)?;
let buffer = arr.get("buffer")?.as_object().cloned().unwrap();
let buffer = JsArrayBuffer::from_object(buffer)?;
let vec = buffer.take()?;

It is suprising that we didn't offer a buffer method on JsUint8Array, so I'll open an issue for it.