refactor(parser): improve safety of char to bytes conversions

[overlookmotel]

to_bytes converts a char to a series of N bytes. Add an assertion to make sure that the character is actually N bytes long.

Also, const assert the value of LOSSY_REPLACEMENT_CHAR_FIRST_BYTE, rather than just a comment stating what we expect it to be.

[overlookmotel]

• refactor(parser): improve safety of char to bytes conversions #13193 👈 (View in Graphite)
• main

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[codspeed-hq]

CodSpeed Instrumentation Performance Report

Merging #13193 will not alter performance

_{Comparing 08-18-refactor_parser_improve_safety_of_char_to_bytes_conversions (6c5f7e5) with main (7fcc51e)¹}

Summary

✅ 34 untouched benchmarks

Footnotes

1. No successful run was found on main (4f8506e) during the generation of this report, so 7fcc51e was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

[Copilot]

Pull Request Overview

This PR enhances the safety of character-to-bytes conversions by adding compile-time assertions. The changes ensure that the to_bytes function correctly handles UTF-8 encoding and validates expected byte values for replacement characters.

• Adds assertions to verify that characters have the expected UTF-8 byte length in to_bytes function
• Replaces a comment with a const assertion to validate the first byte of the lossy replacement character

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
crates/oxc_parser/src/lexer/template.rs	Added assertion to verify character byte length in to_bytes function
crates/oxc_parser/src/lexer/string.rs	Added assertion to to_bytes function and replaced comment with const assertion for replacement character byte value

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[overlookmotel]

I don't think much to argue on this one (despite Copilot's best attempts). So merging without further review.

[overlookmotel]

Merge activity

• Aug 18, 3:14 PM UTC: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
• Aug 18, 5:44 PM UTC: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
• Aug 18, 5:49 PM UTC: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.

[overlookmotel]

Why aren't you merging this, Graphite?