robobun f0295ce0a5 Fix bunfig.toml parsing with UTF-8 BOM (#23276) ...

Fixes #23275

### What does this PR do?

This PR fixes a bug where `bunfig.toml` files starting with a UTF-8 BOM
(byte order mark, `U+FEFF` or bytes `0xEF 0xBB 0xBF`) would fail to
parse with an "Unexpected" error.

The fix uses Bun's existing `File.toSource()` function with
`convert_bom: true` option when loading config files. This properly
detects and strips the BOM before parsing, matching the behavior of
other file readers in Bun (like the JavaScript lexer which treats
`0xFEFF` as whitespace).

**Changes:**
- Modified `src/cli/Arguments.zig` to use `bun.sys.File.toSource()` with
BOM conversion instead of manually reading the file
- Simplified the config loading code by removing intermediate file
handle and buffer logic

### How did you verify your code works?

Added comprehensive regression tests in
`test/regression/issue/23275.test.ts` that verify:
1. ✅ `bunfig.toml` with UTF-8 BOM parses correctly without errors
2. ✅ `bunfig.toml` without BOM still works (regression test)
3. ✅ `bunfig.toml` with BOM and actual config content parses the content
correctly

All three tests pass with the debug build:
```
 3 pass
 0 fail
 11 expect() calls
Ran 3 tests across 1 file. [6.41s]
```

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

---------

Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

2025-10-05 17:22:37 -07:00

..

fixtures

Fix request.url having incorrect port

2023-10-16 15:14:15 -07:00

issue

Fix bunfig.toml parsing with UTF-8 BOM (#23276)

2025-10-05 17:22:37 -07:00