Pr Reviewer

---
name: pr-reviewer
description: "Automated GitHub pull request review workflow with diff analysis, optional lint checks, changed-file risk assessment, security/error-handling/test-coverage findings, and structured review reports. Use when the user asks to review a GitHub PR, inspect a pull request diff, check PR risk, run local lint as part of review, or prepare PR feedback. Requires the gh CLI when fetching GitHub PRs directly."
---

# PR Reviewer

Automated code review for GitHub pull requests and local PR-style diffs. Analyzes diffs for security issues, error handling gaps, style problems, and test coverage.

## Prerequisites

- `gh` CLI installed and authenticated (`gh auth status`)
- Repository access (read at minimum, write for posting comments)
- Optional: `golangci-lint` for Go linting, `ruff` for Python linting

## Quick Start

```bash
# Review all open PRs in current repo
scripts/pr-review.sh check

# Review a specific PR
scripts/pr-review.sh review 42

# Post review as GitHub comment
scripts/pr-review.sh post 42

# Check status of all open PRs
scripts/pr-review.sh status

# List unreviewed PRs (useful for heartbeat/cron integration)
scripts/pr-review.sh list-unreviewed
```

## Configuration

Set these environment variables or the script auto-detects from the current git repo:

- `PR_REVIEW_REPO` — GitHub repo in `owner/repo` format (default: detected from `gh repo view`)
- `PR_REVIEW_DIR` — Local checkout path for lint (default: git root of cwd)
- `PR_REVIEW_STATE` — State file path (default: `./data/pr-reviews.json`)
- `PR_REVIEW_OUTDIR` — Report output directory (default: `./data/pr-reviews/`)

## Directories Written

- **`PR_REVIEW_STATE`** (default: `./data/pr-reviews.json`) — Tracks reviewed PRs and their HEAD SHAs
- **`PR_REVIEW_OUTDIR`** (default: `./data/pr-reviews/`) — Markdown review reports

## What It Checks

| Category | Icon | Examples |
|----------|------|----------|
| Security | 🔴 | Hardcoded credentials, AWS keys, secrets in code |
| Error Handling | 🟡 | Discarded errors (Go `_ :=`), bare `except:` (Python), unchecked `Close()` |
| Risk | 🟠 | `panic()` calls, `process.exit()` |
| Style | 🔵 | `fmt.Print`/`print()`/`console.log` in prod, very long lines |
| TODOs | 📝 | TODO, FIXME, HACK, XXX markers |
| Test Coverage | 📊 | Source files changed without corresponding test changes |

## Smart Re-Review

Tracks HEAD SHA per PR. Only re-reviews when new commits are pushed. Use `review <PR#>` to force re-review.

## Report Format

Reports are saved as markdown files in the output directory. Each report includes:

- PR metadata (author, branch, changes)
- Commit list
- Changed file categorization by language/type
- Automated diff findings with file, line, category, and context
- Test coverage analysis
- Local lint results (when repo is checked out locally)
- Summary verdict: 🔴 SECURITY / 🟡 NEEDS ATTENTION / 🔵 MINOR NOTES / ✅ LOOKS GOOD

## Heartbeat/Cron Integration

Add to a periodic check (heartbeat, cron job, or CI):

```bash
UNREVIEWED=$(scripts/pr-review.sh list-unreviewed)
if [ -n "$UNREVIEWED" ]; then
  scripts/pr-review.sh check
fi
```

## Extending

The analysis patterns in the script are organized by language. Add new patterns by appending to the relevant pattern list in the `analyze_diff()` function:

```python
# Add a new Go pattern
go_patterns.append((r'^\+.*os\.Exit\(', 'RISK', 'Direct os.Exit() — consider returning error'))
```