Code Reviewer

A comprehensive code review skill that analyzes pull requests and code changes for quality, security, maintainability, and best practices.

When This Skill Activates

This skill activates when you:

• Ask for a code review
• Request a PR review
• Mention reviewing changes
• Say "review this" or "check this code"

Review Process

Phase 1: Context Gathering

1. Get changed files

   git diff main...HEAD --name-only
   git log main...HEAD --oneline
   

2. Get the diff

   git diff main...HEAD
   

3. Understand project context

   • Read relevant documentation
   • Check existing patterns in similar files
   • Identify project-specific conventions

Phase 2: Analysis Categories

1. Correctness

• Logic is sound and matches requirements
• Edge cases are handled
• Error handling is appropriate
• No obvious bugs or typos

2. Security

• No hardcoded secrets or credentials
• Input validation and sanitization
• SQL injection prevention
• XSS prevention (for frontend)
• Authentication/authorization checks
• Safe handling of user data

3. Performance

• No N+1 queries
• Appropriate caching
• Efficient algorithms
• No unnecessary computations
• Memory efficiency

4. Code Quality

• Follows DRY principle
• Follows KISS principle
• Appropriate abstractions
• Clear naming conventions
• Proper typing (if TypeScript)
• No commented-out code

5. Testing

• Tests cover new functionality
• Tests cover edge cases
• Test assertions are meaningful
• No brittle tests

6. Documentation

• Complex logic is explained
• Public APIs have documentation
• JSDoc/TSDoc for functions
• README updated if needed

7. Maintainability

• Code is readable
• Consistent style
• Modular design
• Separation of concerns

Phase 3: Output Format

Use this structured format for review feedback:

# Code Review

## Summary
Brief overview of the changes (2-3 sentences).

## Issues by Severity

### Critical
Must fix before merge.

- [ ] **Issue Title**: Description with file:line reference

### High
Should fix before merge unless there's a good reason.

- [ ] **Issue Title**: Description with file:line reference

### Medium
Consider fixing, can be done in follow-up.

- [ ] **Issue Title**: Description with file:line reference

### Low
Nice to have improvements.

- [ ] **Issue Title**: Description with file:line reference

## Positive Highlights
What was done well in this PR.

## Suggestions
Optional improvements that don't require immediate action.

## Approval Status
- [ ] Approved
- [ ] Approved with suggestions
- [ ] Request changes

Common Issues to Check

Security Issues

Performance Issues

Code Quality Issues

Testing Issues

Language-Specific Guidelines

TypeScript

• Use unknown instead of any for untyped values
• Prefer interface for public APIs, type for unions
• Use strict mode settings
• Avoid as assertions when possible

React

• Follow Hooks rules
• Use useCallback/useMemo appropriately (not prematurely)
• Prefer function components
• Use proper key props in lists
• Avoid prop drilling with Context

Python

• Follow PEP 8 style guide
• Use type hints
• Use f-strings for formatting
• Prefer list comprehensions over map/filter
• Use context managers for resources

Go

• Handle errors explicitly
• Use named returns for clarity
• Keep goroutines simple
• Use channels for communication
• Avoid package-level state

Before Approving

Confirm the following:

• All critical issues are addressed
• Tests pass locally
• No merge conflicts
• Commit messages are clear
• Documentation is updated
• Breaking changes are documented

Scripts

Run the review checklist script:

python scripts/review_checklist.py <pr-number>

References

• references/checklist.md - Complete review checklist
• references/security.md - Security review guidelines
• references/patterns.md - Common patterns and anti-patterns