Code Review Checklist

Code Review Checklist

Structured approach to reviewing code changes.

When to Use This Skill

Review Priority Order

1. Security (Critical) - Vulnerabilities, secrets, injection 2. Correctness (High) - Logic errors, breaking changes 3. Performance (Medium) - Inefficiencies, resource leaks 4. Quality (Medium) - Maintainability, readability 5. Style (Low) - Formatting, naming (should be automated)

Security Checklist

Secrets & Credentials

• [ ] No hardcoded API keys, passwords, tokens
• [ ] No credentials in logs or error messages
• [ ] Secrets loaded from environment/vault

Injection Vulnerabilities

• [ ] SQL queries use parameterized statements
• [ ] User input is sanitized before HTML output (XSS)
• [ ] Shell commands don't include user input (command injection)
• [ ] File paths are validated (path traversal)

Authentication & Authorization

• [ ] Auth checks on all protected endpoints
• [ ] Proper session handling
• [ ] Secure password handling (hashing, not plaintext)

Data Exposure

• [ ] Sensitive data not logged
• [ ] API responses don't leak internal details
• [ ] Error messages don't expose system info

Correctness Checklist

Logic

• [ ] Edge cases handled (null, empty, boundary values)
• [ ] Error conditions handled appropriately
• [ ] Async operations properly awaited
• [ ] Race conditions considered

Breaking Changes

• [ ] API contracts maintained
• [ ] Database migrations are reversible
• [ ] Feature flags for risky changes

Testing

• [ ] New code has tests
• [ ] Tests cover error paths, not just happy path
• [ ] Existing tests still pass

Performance Checklist

Efficiency

• [ ] No N+1 queries
• [ ] Appropriate data structures used
• [ ] No unnecessary loops or iterations
• [ ] Caching considered for expensive operations

Resources

• [ ] Database connections closed/pooled
• [ ] File handles closed
• [ ] No memory leaks (event listeners removed, etc.)

Scale

• [ ] Works with realistic data volumes
• [ ] Pagination for large result sets
• [ ] Timeouts on external calls

Quality Checklist

Readability

• [ ] Clear, descriptive names
• [ ] Functions do one thing
• [ ] No overly complex conditionals
• [ ] Comments explain "why", not "what"

Maintainability

• [ ] DRY (no copy-paste duplication)
• [ ] Appropriate abstractions
• [ ] Dependencies are justified
• [ ] No dead code

Consistency

• [ ] Follows project patterns
• [ ] Matches existing code style
• [ ] Uses established utilities/helpers

Review Output Format

## Review: [PR Title]

**Risk Level**: LOW | MEDIUM | HIGH | CRITICAL

### Critical Issues
1. [Category] Description (file:line)
   - Impact: What could go wrong
   - Fix: Specific recommendation

### Suggestions
1. [Category] Description (file:line)
   - Why: Reasoning
   - Consider: Alternative approach

### Positive Notes
- [Recognition of good patterns]

Quick Checks

For fast reviews, at minimum check: 1. Any secrets or credentials? 2. Any SQL/command injection? 3. Are error cases handled? 4. Do tests exist for new code?