Panic: "called Option::unwrap() on a None value"

[charlyisidore]

I am using the current git version of minify-js. The following issue happens from version 0.6.0 (0.5.6 works fine).

When I try minify the code if (a) a, I get the following error with RUST_BACKTRACE=1:

thread 'main' panicked at /home/user/.cargo/git/checkouts/minify-js-4f5cda0ad742d80b/77dae36/rust/src/minify/pass1.rs:379:81:
called `Option::unwrap()` on a `None` value
stack backtrace:
   0: rust_begin_unwind
             at /rustc/e51e98dde6a60637b6a71b8105245b629ac3fe77/library/std/src/panicking.rs:645:5
   1: core::panicking::panic_fmt
             at /rustc/e51e98dde6a60637b6a71b8105245b629ac3fe77/library/core/src/panicking.rs:72:14
   2: core::panicking::panic
             at /rustc/e51e98dde6a60637b6a71b8105245b629ac3fe77/library/core/src/panicking.rs:144:5
   3: core::option::Option<T>::unwrap
             at /rustc/e51e98dde6a60637b6a71b8105245b629ac3fe77/library/core/src/option.rs:931:21
   4: <minify_js::minify::pass1::Pass1 as parse_js::visit::Visitor>::on_syntax_up
             at /home/user/.cargo/git/checkouts/minify-js-4f5cda0ad742d80b/77dae36/rust/src/minify/pass1.rs:379:33
   5: parse_js::visit::Visitor::visit
             at /home/user/.cargo/registry/src/index.crates.io-6f17d22bba15001f/parse-js-0.21.0/src/visit.rs:475:7
   6: parse_js::visit::Visitor::visit
             at /home/user/.cargo/registry/src/index.crates.io-6f17d22bba15001f/parse-js-0.21.0/src/visit.rs:77:11
   7: minify_js::minify::minify_js
             at /home/user/.cargo/git/checkouts/minify-js-4f5cda0ad742d80b/77dae36/rust/src/minify/mod.rs:36:3
   8: minify_js::minify
             at /home/user/.cargo/git/checkouts/minify-js-4f5cda0ad742d80b/77dae36/rust/src/lib.rs:50:3
   9: minify_js_bugfix::main
             at ./src/main.rs:9:5
  10: core::ops::function::FnOnce::call_once
             at /rustc/e51e98dde6a60637b6a71b8105245b629ac3fe77/library/core/src/ops/function.rs:250:5
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

The error happens here:

minify-js/rust/src/minify/pass1.rs

Line 379 in 77dae36

let closure_scope = scope.find_self_or_ancestor(|t| t.is_closure()).unwrap();

Please find below the code to reproduce the error:

• src/main.rs:

use minify_js::{minify, Session, TopLevelMode};

fn main() -> anyhow::Result<()> {
    let input: &str = "if (a) a";

    let session = Session::new();
    let mut output = Vec::new();

    minify(
        &session,
        TopLevelMode::Global,
        input.as_bytes(),
        &mut output,
    ).map_err(|e| anyhow::anyhow!(e.to_string()))?;

    println!("{}", String::from_utf8(output)?);

    Ok(())
}

• Cargo.toml:

[package]
name = "minify_js_issue"
version = "0.1.0"
edition = "2021"
publish = false

[dependencies]
anyhow = "1.0.79"
minify-js = { git = "https://github.com/wilsonzlin/minify-js", version = "0.6.0" }

Many thanks for this great library.

[organnerx]

Same problem. Until it get fixed you can modify input js file to have 1 big IIFE:
"use strict";
(() => {
// your code goes here;
})();