review-diff

Scan a git diff for project-specific anti-patterns. This is a fast, targeted scan (seconds), not a full code review. Use /review for comprehensive analysis.

Step 0: Detect project

Ensure you are inside a git repository before running diff commands:

• If cwd is a git repo: use it
• If recent context references a project: cd into it first
• Check CLAUDE.md or the project manifest (package.json, composer.json, pom.xml, Gemfile, *.csproj, go.mod, Cargo.toml, requirements.txt/pyproject.toml, etc.) in the project root to identify the framework and project-specific patterns
• If unclear: ask which project

Step 1: Get the diff

Determine the diff source from $ARGUMENTS:

• No arguments: Run git diff (unstaged) + git diff --cached (staged). Combine both outputs.
• Branch name (e.g., feat/xyz): Run git diff main...$ARGUMENTS
• Commit range (e.g., HEAD~3..HEAD): Run git diff $ARGUMENTS
• Single commit hash: Run git diff $ARGUMENTS~1..$ARGUMENTS

If the diff is empty, report "No changes to scan." and stop.

Step 2: Scan for anti-patterns

Analyze ONLY + lines (additions) in the diff. For each pattern below, search the added lines and the surrounding file context when needed.

Pattern Table

Step 3: Build findings table

For each finding, extract:

• File: from the diff +++ b/... header
• Line: calculate from @@ -X,Y +Z,W @@ hunk headers by counting + lines
• Pattern: the pattern name from the table above
• Finding: the specific line or code that triggered the match
• Recommendation: what to change

Output format:

| # | Severity | File | Line | Pattern | Finding | Recommendation |
|---|----------|------|------|---------|---------|----------------|
| 1 | CRITICAL | path/to/file.ts | 42 | Soft-delete | `.delete({ where: ... })` | Use `update({ is_active: false, deleted_at: new Date() })` |

If no findings: "No anti-patterns detected in the diff. GO."

Step 4: Summary

Review-diff: X findings (Y critical, Z high, W medium, V low)
Verdict: GO / REVIEW NEEDED

• GO: 0 critical, 0 high findings
• REVIEW NEEDED: any critical or high findings present