thread main panicked on Result::unwrap() with simple js file

[reklis]

> cat index2.js
const io

> bat index2.js
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: 
Error(-114, target of repeat operator is invalid)', libcore/result.rs:945:5

This appears to be syntax related, if I change the file name to .py it works

> mv index2.js index2.py

> bat index2.py
───────┬────────────────────────────────────────────────────────────────────
       │ File index2.py
───────┼────────────────────────────────────────────────────────────────────
   1   │ const io
───────┴────────────────────────────────────────────────────────────────────

I'm using the sample from the readme for the syntax definitions

mkdir -p ~/.config/bat/syntax
cd ~/.config/bat/syntax

# Download some language definition files, for example:
git clone https://github.com/sublimehq/Packages/
rm -rf Packages/Markdown
git clone https://github.com/jonschlinkert/sublime-markdown-extended

[sharkdp]

Yes, this is related to the JavaScript.sublime-syntax file in https://github.com/sublimehq/Packages/ which contains a regular expression that syntect can not parse. I have already addressed this upstream (trishume/syntect#156) and opened a pull request to fix this in sublimehq/Packages (sublimehq/Packages#1525).

bat currently ships with a manually-patched version of the JavaScript syntax:

diff --git a/JavaScript/JavaScript.sublime-syntax b/JavaScript/JavaScript.sublime-syntax
index 93a478f..8ebb1d0 100644
--- a/JavaScript/JavaScript.sublime-syntax
+++ b/JavaScript/JavaScript.sublime-syntax
@@ -15,7 +15,7 @@ variables:
   identifier: '{{identifier_start}}{{identifier_part}}*{{identifier_break}}'
   constant_identifier: '[[:upper:]]{{identifier_part}}*{{identifier_break}}'
   dollar_only_identifier: '\${{identifier_break}}'
-  dollar_identifier: '(\$){{identifier_part}}*{{identifier_break}}+'
+  dollar_identifier: '(\$){{identifier_part}}*{{identifier_break}}'
   func_lookahead: '\s*(async\s+)?function{{identifier_break}}'
   arrow_func_lookahead: '\s*(async\s*)?({{identifier}}|\(([^()]|\([^()]*\))*\))\s*=>'
   either_func_lookahead: (?:{{func_lookahead}}|{{arrow_func_lookahead}})

[sharkdp]

This should be fixed, my upstream PR has been merged.