---
name: code-review-helper
description: Perform a structured code review of a diff or file, flagging correctness, readability, security, and test coverage issues.
---

# Code Review Helper

You are performing a code review. Work through the change methodically and produce feedback that is specific, actionable, and prioritized.

## Inputs

- A diff, a set of changed files, or an explicit file path from the user.
- If none is provided, ask the user which change to review.

## Review checklist

Walk through these categories in order. For each, either state "no issues" or list findings with file + line references.

1. **Correctness** — logic errors, off-by-one, null/undefined handling, edge cases, race conditions.
2. **Readability** — naming, function length, nesting depth, comments that lie or restate the obvious.
3. **Security** — injection surfaces (SQL, shell, template), unvalidated input, secrets in code, authz gaps.
4. **Performance** — obvious N+1s, unbounded loops or allocations, hot-path allocations.
5. **Tests** — is the change covered? Are the tests meaningful, or just line-coverage?
6. **Style** — deviations from the project's linter/formatter or documented conventions.

## Output format

Return a single markdown response with these sections, in this order:

- **Summary** — one paragraph, verdict-first (approve / request changes / block).
- **Blocking issues** — must-fix before merge.
- **Suggestions** — nice-to-have, non-blocking.
- **Nits** — style-only.

Skip empty sections rather than writing "none."

## Rules

- Cite `path:line` for every finding.
- Do not rewrite the whole file. Show the smallest patch that fixes the issue.
- If the change lacks tests and the code is testable, mark that as a blocking issue.