Code Review Checklist

Code Review Checklist

Issue Prioritization

Critical (Must Fix Before Merge)

• Security vulnerabilities
• Data loss risks
• Breaking changes without migration
• Test failures
• Build failures

Warnings (Should Fix)

• Performance issues
• Code quality violations
• Missing error handling
• Incomplete documentation
• Test coverage gaps

Suggestions (Nice to Have)

• Refactoring opportunities
• Code style improvements
• Additional test cases
• Documentation enhancements

Security Review (OWASP Top 10)

Injection (SQL, Command, XSS)

• Parameterized queries or ORM (no string concatenation in SQL)
• Input sanitization before rendering in templates
• Command arguments properly escaped
• User input never directly in file paths

Authentication & Authorization

• Endpoints protected with @PreAuthorize or equivalent
• Role checks at service layer, not just controller
• Session management follows best practices
• Password handling uses secure hashing (bcrypt)

Sensitive Data Exposure

• No secrets in code or logs
• PII protected in transit (HTTPS) and at rest
• Error messages don't leak internal details
• Debug endpoints disabled in production

CSRF & CORS

• CSRF tokens required for state-changing operations
• CORS policy restricts allowed origins
• SameSite cookie attribute set appropriately

Performance Review

Backend

• N+1 query patterns avoided (use JOIN FETCH or @EntityGraph)
• Pagination for list endpoints
• Appropriate indexes on frequently queried columns
• Caching for expensive computations
• Async processing for long-running tasks

Frontend

• Large lists virtualized
• Images optimized and lazy-loaded
• Bundle size not significantly increased
• Memoization for expensive renders (useMemo, React.memo)
• No unnecessary re-renders (check dependency arrays)

Database

• Migrations are reversible
• New indexes don't impact write performance excessively
• Large data operations batched

Code Quality Standards

DRY (Don't Repeat Yourself)

• No copy-pasted logic that should be abstracted
• Shared utilities extracted appropriately
• Configuration centralized

SOLID Principles

• Single Responsibility: Classes/functions do one thing
• Open/Closed: Extensible without modification
• Liskov Substitution: Subtypes substitutable for base types
• Interface Segregation: Interfaces are focused
• Dependency Inversion: Depend on abstractions

Readability

• Clear, descriptive naming
• Functions are reasonably sized (<50 lines)
• Complex logic has comments explaining "why"
• Consistent code style (enforced by formatters)

Error Handling

• Errors caught and handled appropriately
• User-facing error messages are helpful
• Errors logged with sufficient context
• Recovery paths where appropriate

Test Coverage Assessment

Unit Tests

• New public methods have tests
• Edge cases covered (null, empty, boundary values)
• Error paths tested
• Mocks used appropriately (not over-mocked)

Integration Tests

• API endpoints tested with realistic data
• Database interactions verified
• External service integrations stubbed

E2E Tests

• Critical user flows covered
• Happy path and main error cases
• Cross-browser testing for UI changes

Review Output Format

## Code Quality Findings

### Critical Issues (Must Fix)
- [File:Line] Issue description
  - Why it's critical
  - Suggested fix

### Warnings (Should Fix)
- [File:Line] Issue description
  - Impact
  - Suggested fix

### Suggestions (Nice to Have)
- [File:Line] Improvement opportunity
  - Benefit
  - How to implement