REPL panics related to invalid unicode

[solson]

I found a way to trip two different Rust panic messages in the REPL:

$ deno --version
deno 1.4.6
v8 8.7.220.3
typescript 4.0.3

$ deno
Deno 1.4.6
exit using ctrl+d or close()
> '\u{1f3b5}'
"🎵"
> '\u{1f3b5}'[0]
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Error("unexpected end of hex escape", line: 1, column: 60)', cli/inspector.rs:859:54
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
fatal runtime error: failed to initiate panic, error 5
fish: “deno” terminated by signal SIGABRT (Abort)

$ deno
Deno 1.4.6
exit using ctrl+d or close()
> '\u{1f3b5}'[1]
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Error("lone leading surrogate in hex escape", line: 1, column: 59)', cli/inspector.rs:859:54
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
fatal runtime error: failed to initiate panic, error 5
fish: “deno” terminated by signal SIGABRT (Abort)

Note that these panics only occur in the REPL, and regular Deno code is unaffected as far as I can tell.

cc @caspervonb

[caspervonb]

Thanks for the heads up 👍

For reference, It's from a StringBuffer unwrap in the inspector so it only happens for local inspector message responses that contains invalid unicode.

deno/cli/inspector.rs

Lines 854 to 868 in 1956cb8

	fn send_response(
	&mut self,
	call_id: i32,
	message: v8::UniquePtr<v8::inspector::StringBuffer>,
	) {
	let raw_message = message.unwrap().string().to_string();
	let message = serde_json::from_str(&raw_message).unwrap();
	self
	.response_tx_map
	.remove(&call_id)
	.unwrap()
	.send(message)
	.unwrap();
	}

[benjamingr]

Hey, I want to try and take a look at this as it's a relatively small fix that will make it learn some rust :]

[benjamingr]

Checked this for a bit, I think this actually isn't actually a small fix at all to do well. The "invalid" JSON is coming from the CDP itself, Chrome's JSON parser and other parsers I've found happily parse this and it seems like an issue with serde_json itself.

I will however take the opportunity to brush up on rust error handling and match expressions and try to solve the issue ad-hoc :]

[bartlomieju]

Fixed in #8759