[ilaigold]

Summary

After the C++ (#1279) and Go (#1235) raw-string fixes, I tried C# raw strings against the same masking code and they break in a similar way. C# 11 lets a raw string open with four or more quotes so the content can contain """. mask_c_style_source treats any """ as a plain triple quote, so it closes the literal at the first inner """, opens a new string on the leftover quotes and masks the rest of the file.

With this file:

class Before {}
class Service {
  string Text = """"
    { "a": """ }
    """";
  void Visible() {}
}
class After {}

the preview stops at class Service, and method Service.Visible and class After are gone. One-line literals like """"" contains """" and { """"" hit the same thing.

Changes

• For .cs files, match the whole opening quote run and close on a run of the same length, using the raw_terminator path that C++ and Go raw strings already go through. Three-quote literals close exactly as before, and triple quotes in other languages are untouched.
• Add a parametrized test in tests/test_rank_preview.py with three-, four- and five-quote literals that contain braces, with declarations before and after.

Interpolated raw strings ($$"""") take the same path, since the $ prefix passes through before the quote run. I checked one by hand with {{x}} and """ inside: main drops Service.Visible and After, this branch keeps them. Verbatim @"""" strings and "" + "{" give the same outline on both.

Testing

On macOS with Python 3.12, Node 24.21.0 and pnpm 11.25.0:

• ruff check and ruff format --check with plugins/codex-security/pyproject.toml: pass
• pnpm --dir sdk/typescript run build:ci: pass
• node .github/scripts/check_plugin_source_compatibility.mjs: pass, and its node --test suite: 9 passed
• python -m pytest plugins/codex-security/tests -q -n 4 --dist worksteal --max-worker-restart 0: 1622 passed, 3 skipped

With main's rank_preview.py, the four-quotes and five-quotes cases fail (the outline stops at class Service) and three-quotes still passes. With the fix, all 144 tests in test_rank_preview.py pass.

Risk and rollout

Only .cs structural previews change, and only for literals that open with four or more quotes. No CLI, schema or migration changes.

Public disclosure review

• No customer, partner, prospect, or user identities, data, or identifying details are included.
• No credentials, personal data, private source, scan findings, or nonpublic links or tickets are included.
• I reviewed the branch name, title, description, commits, changes, comments, logs, screenshots, attachments, and links for public disclosure.

🤖 Generated with Claude Code

[mldangelo-oai]

Thanks for the clear reproduction and focused fix. Valid C# raw strings with longer delimiters were hiding later methods and classes from ranking previews. Matching the opening quote count through the existing raw-string state fixes that without adding another parser path.

I reproduced the before/after behavior and checked ordinary, verbatim, and representative interpolated strings. The 144 preview tests, Ruff lint/format, TypeScript CI build, and both portable source compatibility checks passed locally. The parameterized regression cases are proportionate to the change. Approved.