Review

Code Quality Skill

Purpose

Perform systematic code reviews, identify issues, suggest refactorings, and enforce best practices. Acts as an automated code reviewer catching problems before they reach production.

Activation Triggers

Activate this skill when:

• User says "review this code"
• User asks "can this be improved?"
• User mentions "refactoring", "optimization", or "code smell"
• Before git commits (pre-commit review)
• After completing a feature
• User says "is this code good?"

Comprehensive Review Checklist

1. Code Structure

Single Responsibility Principle (SRP)

• Check: Each function/class has one clear purpose
• Red Flag: Functions doing multiple unrelated things
• Fix: Split into focused, single-purpose functions

DRY (Don't Repeat Yourself)

• Check: No duplicated logic
• Red Flag: Copy-pasted code blocks
• Fix: Extract to shared function/utility

Function Length

• Check: Functions under 50 lines (prefer under 30)
• Red Flag: Functions over 100 lines
• Fix: Break into smaller, composable functions

Naming Clarity

• Check: Names clearly describe purpose
• Red Flag: Vague names (data, info, temp, x, y)
• Fix: Use descriptive, intention-revealing names

Magic Numbers

• Check: Constants are named
• Red Flag: Unexplained numbers in code
• Fix: Extract to named constants

2. Error Handling

All Errors Caught

• Check: Error handling around risky operations
• Red Flag: Unhandled exceptions, missing error handling
• Fix: Add comprehensive error handling

No Silent Failures

• Check: Errors are logged or surfaced
• Red Flag: Empty catch blocks, ignored errors
• Fix: Log errors with context, alert user appropriately

User-Friendly Error Messages

• Check: Errors explain what went wrong and what to do
• Red Flag: Technical jargon exposed to users
• Fix: Translate technical errors to user language

Logging for Debugging

• Check: Appropriate logging at key points
• Red Flag: No logging or excessive logging
• Fix: Add structured logging with context

Edge Cases Covered

• Check: Boundary conditions handled (null, empty, zero)
• Red Flag: Assumptions about inputs
• Fix: Add defensive checks and validation

3. Security

Input Validation

• Check: All user inputs validated and sanitized
• Red Flag: Raw user input used directly
• Fix: Add validation with schema validation library

SQL Injection Prevention

• Check: Parameterized queries or ORM used
• Red Flag: String concatenation in SQL
• Fix: Use prepared statements or ORM methods

XSS Prevention

• Check: HTML output escaped, CSP headers set
• Red Flag: Raw HTML rendering of user content
• Fix: Use safe rendering or sanitize before output

Sensitive Data Handling

• Check: Passwords hashed, PII encrypted, secure transmission
• Red Flag: Plain text secrets, sensitive data in logs
• Fix: Use bcrypt/argon2, encrypt at rest, sanitize logs

Environment Variables for Secrets

• Check: API keys, credentials in environment or secret manager
• Red Flag: Hardcoded credentials in code
• Fix: Move to environment variables, use secret managers

4. Performance

No N+1 Queries

• Check: Batch queries, eager loading used
• Red Flag: Query inside loop
• Fix: Use includes/joins, batch operations

Appropriate Caching

• Check: Expensive operations cached
• Red Flag: Repeated identical API calls or computations
• Fix: Add caching layer (Redis, in-memory, etc.)

Database Indexes

• Check: Indexed columns used in WHERE/JOIN clauses
• Red Flag: Full table scans on large tables
• Fix: Add indexes on frequently queried columns

Unnecessary Computations

• Check: Early returns, lazy evaluation
• Red Flag: Work done before checking preconditions
• Fix: Move expensive operations after validation

Memory Leak Prevention

• Check: Resources cleaned up, connections closed
• Red Flag: Growing collections, unclosed connections
• Fix: Add cleanup in finally blocks, use resource management patterns

5. Testing

Tests Exist

• Check: Tests cover new functionality
• Red Flag: No tests for new code
• Fix: Write tests for all new functions/components

Edge Cases Tested

• Check: Boundary conditions handled
• Red Flag: Only happy path tested
• Fix: Add tests for edge cases and error conditions

Happy Path Tested

• Check: Normal operation verified
• Red Flag: No positive test cases
• Fix: Add tests for expected behavior

Error Conditions Tested

• Check: Invalid inputs, failures handled
• Red Flag: Error paths not verified
• Fix: Add tests for error scenarios

Tests Are Maintainable

• Check: Clear test names, minimal duplication
• Red Flag: Complex test setup, brittle assertions
• Fix: Extract test helpers, use clear assertions

Review Process

Step 1: Determine Scope

Ask user what to review:

1. Current staged changes (git diff --cached)
2. Current unstaged changes (git diff)
3. Specific file or directory
4. Entire feature
5. Recent commits

Step 2: Analyze Code

Run appropriate git diff or read files:

# For staged changes
git diff --cached

# For unstaged changes
git diff

# For specific file
Read file_path

# For feature
git diff main...HEAD

Step 3: Apply Checklist

Systematically go through:

1. Code Structure (5 checks)
2. Error Handling (5 checks)
3. Security (5 checks)
4. Performance (5 checks)
5. Testing (5 checks)

UltraThink Architectural Issues: If review reveals fundamental architectural problems, activate deep thinking:

Say: "This code has architectural issues. Let me ultrathink whether refactoring or redesign is needed."

When to UltraThink:

• Code violates multiple principles (SRP, DRY, YAGNI)
• Tight coupling makes testing difficult
• Similar logic duplicated across multiple files
• Error handling is scattered and inconsistent
• Performance issues suggest wrong data structure/algorithm

Question deeply:

• Is this a symptom of wrong architecture?
• Would refactoring fix root cause or just move complexity?
• What would this look like if designed from scratch?
• What's preventing clean separation of concerns?
• Is the domain model wrong?

After UltraThink: Recommend tactical fixes (refactor) vs. strategic redesign with clear reasoning.

Step 4: Generate Review Report

Review Output Format

## Code Review: [File/Feature Name]

### Strengths

[List what's done well - be specific and encouraging]
- Clear function naming in authentication module
- Comprehensive error handling for API calls
- Good test coverage (87%)

### Issues Found

#### Priority: High - Must Fix Before Merge
1. **[Issue Title]**
   - **Location:** `file:line`
   - **Problem:** [Specific description]
   - **Risk:** [What could go wrong]
   - **Fix:** [How to resolve]

#### Priority: Medium - Should Address
1. **[Issue Title]**
   - **Location:** `file:line`
   - **Problem:** [Description]
   - **Impact:** [Effect on code quality]
   - **Suggestion:** [Improvement approach]

#### Priority: Low - Consider Improving
1. **[Issue Title]**
   - **Location:** `file:line`
   - **Note:** [Observation]
   - **Enhancement:** [Optional improvement]

### Refactoring Suggestions

#### Suggestion 1: [Title]
**Current Code:**
[Show problematic pattern]

**Refactored Code:**
[Show improved version]

**Benefits:**
- [Benefit 1]
- [Benefit 2]

### Code Metrics

- **Complexity:** [Low/Medium/High]
- **Test Coverage:** [X%]
- **Maintainability:** [A/B/C/D/F]
- **Lines of Code:** [N]
- **Duplicated Code:** [X%]

### Action Items

- [ ] Fix high-priority issues
- [ ] Address medium-priority items
- [ ] Consider refactoring suggestions
- [ ] Add tests for uncovered paths
- [ ] Update documentation

---

**Overall Assessment:** [Summary statement]
**Recommendation:** [Approve/Request Changes/Reject]

[Confidence: X.X]

Examples

Example 1: Pre-Commit Review

User: "I'm about to commit, can you review my changes?"

Process:

1. Run git diff --cached to see staged changes
2. Identify changed files
3. Apply 25-point checklist
4. Generate report with priorities

Focus on: Input validation, error handling, security, and test coverage for new code.

Example 2: Refactoring Request

User: "Can you suggest improvements for this module?"

Process:

1. Read the file(s)
2. Identify code smells: magic numbers, duplicated logic, long functions
3. Propose specific refactorings with before/after pseudocode
4. Explain benefits of each change

Focus on: Named constants, extracted functions, input validation, and cleaner error handling.

Integration Points

• Works with spec-driven-implementation skill during execution phase
• Works with git-workflow skill for pre-commit reviews
• Works with systematic-debug skill to verify test quality
• Triggered automatically before commits if integrated

Notes

• Be thorough but constructive
• Prioritize issues appropriately
• Always provide specific code examples
• Explain WHY something is an issue, not just WHAT
• Offer concrete solutions, not just criticism
• Balance between perfectionism and pragmatism
• Focus on high-impact improvements