Deno panics when console.log(String.fromCharCode(55296)) is run in REPL

[jed]

Per this convo.

When I perform the following (on macos x86_64 v1.20.4),

1. run RUST_BACKTRACE=1 deno to open a REPL, then
2. enter console.log(String.fromCharCode(55296)) and press enter

deno panics and outputs the following backtrace:

thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Error("unexpected end of hex escape", line: 1, column: 101)', /private/tmp/deno-20220406-92106-p4p5kp/deno/core/inspector.rs:724:66
stack backtrace:
   0: _rust_begin_unwind
   1: core::panicking::panic_fmt
   2: core::result::unwrap_failed
   3: core::result::Result<T,E>::unwrap
   4: <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll
   5: <futures_util::future::select::Select<A,B> as core::future::future::Future>::poll
   6: <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll
   7: <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll
   8: <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll
   9: <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll
  10: <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll
  11: deno::tools::repl::run::{{closure}}
  12: <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll
  13: deno::main::{{closure}}
  14: <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll
  15: deno_runtime::tokio_util::run_basic
  16: deno::main
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

According to other folks on Discord, the same behavior happens for other architectures.

[bartlomieju]

Turns out it's a duplicate of #12226

[lucacasonato]

It turns out it's actually not exactly a duplicate of #12226, although they are related. This one can be fixed with a lot less effort than #12226 though. PR is incoming!

[rotu]

How is this not an exact duplicate?

[lucacasonato]

@rotu you're right. It's an exact duplicate. I confused #12226 with another issue.