PR Reviewer

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

Prerequisites

• Python 3.12+
• 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

# Review all open PRs in current repo
python scripts/pr_review.py check

# Review a specific PR
python scripts/pr_review.py review 42

# Post review as GitHub comment
python scripts/pr_review.py post 42

# Check status of all open PRs
python scripts/pr_review.py status

# List unreviewed PRs (useful for heartbeat/cron integration)
python scripts/pr_review.py 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/)

What It Checks

Category	Marker	Examples
Security	[FAIL]	Hardcoded credentials, AWS keys, secrets in code
Error Handling	[WARNING]	Discarded errors (Go _ :=), bare except: (Python), unchecked Close()
Risk	[WARNING]	panic() calls, process.exit()
Style	[NOTE]	fmt.Print/print()/console.log in prod, very long lines
TODOs	[NOTE]	TODO, FIXME, HACK, XXX markers
Test Coverage	[NOTE]	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.

Unavailable GitHub, JSON, or review state inputs fail with actionable stderr and a non-zero exit. The CLI should not treat broken gh responses, malformed JSON, or unreadable state as "no open PRs" or "no findings."

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: [FAIL] SECURITY / [WARNING] NEEDS ATTENTION / [NOTE] MINOR NOTES / [OK] LOOKS GOOD

Heartbeat/Cron Integration

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

UNREVIEWED=$(python scripts/pr_review.py list-unreviewed)
if [ -n "$UNREVIEWED" ]; then
  python scripts/pr_review.py check
fi

Extending

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

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