Commit Graph

1 Commits

Author SHA1 Message Date
robobun
f5ef9cda3c Fix panic in JavaScript lexer when parsing invalid template strings in JSX (#21967)
## Summary

- Fixes a crash where invalid slice bounds caused a panic with message:
"start index N is larger than end index M"
- The issue occurred in `js_lexer.zig:767` when calculating string
literal content slice bounds
- Adds proper bounds checking to prevent slice bounds violations
- Includes regression test to prevent future occurrences

## Root Cause

The crash happened when `suffix_len` was larger than `lexer.end`,
causing the calculation `lexer.end - suffix_len` to result in a value
smaller than the `base` position. This created invalid slice bounds like
`[114..113]`.

## Solution

Added bounds checking to ensure:
1. `end_pos` is calculated safely: `if (lexer.end >= suffix_len)
lexer.end - suffix_len else lexer.end`
2. `slice_end` is always >= `base`: `@max(base, end_pos)`

## Test Plan

- [x] Added regression test in
`test/regression/issue/jsx-template-string-crash.test.ts`
- [x] Test verifies no crashes occur with JSX template string patterns
- [x] Verified normal template string functionality still works
- [x] All tests pass

🤖 Generated with [Claude Code](https://claude.ai/code)

---------

Co-authored-by: Jarred Sumner <jarred@jarredsumner.com>
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
2025-08-19 18:47:04 -07:00