cannot access 'i' before initialization

[lastmjs]

Describe the bug

I am trying to use an npm package called elliptic. This is a popular library, and with that knowledge it is a safe assumption that it works well in the common JS engines. I have tested it locally in Node.js and it works fine.

Unfortunately when trying to import the most basic functionality in Boa, this error is thrown:

cannot access 'i' before initialization

I have looked through the source code, and the variable referenced in the error is always declared with var and never const or let, so I don't think this error should be thrown.

To Reproduce

Just throw this code into a Boa script and execute it: https://github.com/indutny/elliptic/blob/master/dist/elliptic.min.js

The error will be thrown.

Expected behavior

This error should not be thrown, and the code should work just fine.

Build environment (please complete the following information):

I don't believe this information is relevant.

• OS: Ubuntu
• Version: 20.04
• Target triple: wasm32-unknown-unknown and probably all triples
• Rustc version: rustc 1.66.1 (90743e729 2023-01-10)

Additional context

I believe this issue has a high likelihood of being related: #1393

[jedel1043]

Huh, I tried to reproduce it in the main branch but it successfully runs. Are you maybe running it in the 0.16v?

[lastmjs]

I've reproduced it with multiple versions, let me double check.

[lastmjs]

I can confirm that the issue presents on the latest commit hash on main.

Here's the commit hash: cf85843

Here's the Cargo.toml that I'm using:

[package]
name = "boa_uint8array"
version = "0.0.0"
edition = "2018"

[dependencies]
boa_engine = { git = "https://github.com/boa-dev/boa", rev = "cf85843dc838c7c36e6b635b34f31d100e64c63b" }

[lastmjs]

Did you ensure to paste this exact minified code in? https://github.com/indutny/elliptic/blob/master/dist/elliptic.min.js

[lastmjs]

Here's the Rust without that minified code pasted in without modification:

fn main() {
    let mut context = boa_engine::Context::default();

    let exports_js_value = context
        .eval_script(boa_engine::Source::from_bytes(r#""#))
        .unwrap();

    println!("{:#?}", exports_js_value);
}

[jedel1043]

Finally could reproduce the issue, I was accidentally running the unminified script instead of the minified one 😅

The upside is that elliptic.js does work without problems, it's just the minified version the one that is giving the engine some trouble. I'll put this in the pre-v1 tracker, and I'll probably debug it next week.

[lastmjs]

I think the issue still presents when you try to use the library using the non-minified version, unfortunately.

[jedel1043]

Yeah, and it seems to be the same issue. I tried to create an encryption context using the EC constructor with:

let script = include_bytes!("test.js");

    let context = &mut Context::default();

    match context.eval_script(Source::from_bytes(script)) {
        Ok(v) => println!("{}", v.display()),
        Err(e) => eprintln!("{}", e),
    }

    let elliptic = context
        .global_object()
        .clone()
        .get("elliptic", context)
        .unwrap()
        .as_object()
        .unwrap()
        .clone();
    let constructor = elliptic
        .get("ec", context)
        .unwrap()
        .as_object()
        .unwrap()
        .clone();

    match constructor.construct(&["curve25519".into()], None, context) {
        Ok(v) => println!(
            "{}",
            JsValue::new(v)
                .to_string(context)
                .unwrap()
                .to_std_string_escaped()
        ),
        Err(e) => eprintln!("{}", e),
    }

and it returned:

ReferenceError: cannot access 'r' before initialization

Seems to be the same problem of var binding.