github-code-review

GitHub Code Review

Perform code reviews on local changes before pushing, or review open PRs on GitHub. Most of this skill uses plain git — the gh/curl split only matters for PR-level interactions.

Prerequisites

• Authenticated with GitHub (GITHUB_TOKEN env var or gh auth login)
• Inside a git repository

Setup (for PR interactions)

if command -v gh &>/dev/null && gh auth status &>/dev/null; then
  AUTH="gh"
else
  AUTH="git"
fi

REMOTE_URL=$(git remote get-url origin)
OWNER_REPO=$(echo "$REMOTE_URL" | sed -E 's|.*github\.com[:/]||; s|\.git$||')
OWNER=$(echo "$OWNER_REPO" | cut -d/ -f1)
REPO=$(echo "$OWNER_REPO" | cut -d/ -f2)

---

1. Reviewing Local Changes (Pre-Push)

This is pure git — works everywhere, no API needed.

Get the Diff

# Staged changes (what would be committed)
git diff --staged

# All changes vs main (what a PR would contain)
git diff main...HEAD

# File names only
git diff main...HEAD --name-only

# Stat summary (insertions/deletions per file)
git diff main...HEAD --stat

Review Strategy

1. Get the big picture first:

git diff main...HEAD --stat
git log main..HEAD --oneline

1. Review file by file — use read_file on changed files for full context:

git diff main...HEAD -- src/auth/login.py

1. Check for common issues:

# Debug statements, TODOs, console.logs left behind
git diff main...HEAD | grep -n "print(\|console\.log\|TODO\|FIXME\|HACK\|XXX\|debugger"

# Large files accidentally staged
git diff main...HEAD --stat | sort -t'|' -k2 -rn | head -10

# Secrets or credential patterns
git diff main...HEAD | grep -in "password\|secret\|api_key\|token.*=\|private_key"

# Merge conflict markers
git diff main...HEAD | grep -n "<<<<<<\|>>>>>>\|======="

1. Present structured feedback to the user.

Review Output Format

## Code Review Summary

### Critical
- **src/auth.py:45** — SQL injection: user input passed directly to query.
  Suggestion: Use parameterized queries.

### Warnings
- **src/models/user.py:23** — Password stored in plaintext. Use bcrypt or argon2.
- **src/api/routes.py:112** — No rate limiting on login endpoint.

### Suggestions
- **src/utils/helpers.py:8** — Duplicates logic in `src/core/utils.py:34`. Consolidate.
- **tests/test_auth.py** — Missing edge case: expired token test.

### Looks Good
- Clean separation of concerns in the middleware layer
- Good test coverage for the happy path