# Code Review Checklist

> Code review guidelines covering code quality, security, and best practices.

- Skill: `whd4/code-review-checklist` (Agent Skill)
- Install (CLI): `npx skillmds add whd4/code-review-checklist`
- Raw SKILL.md: https://api.skillmd.com/api/skills/whd4/code-review-checklist/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Security
- Author: whd4 (https://skillmd.com/u/whd4)
- Updated: 2026-09-09
- Page: https://skillmd.com/skills/whd4/code-review-checklist

---


# Code Review Checklist

## Quick Review Checklist

### Correctness

- [ ] Code does what it's supposed to do
- [ ] Edge cases handled
- [ ] Error handling in place
- [ ] No obvious bugs

### Security

- [ ] Input validated and sanitized
- [ ] No SQL/NoSQL injection vulnerabilities
- [ ] No XSS or CSRF vulnerabilities
- [ ] No hardcoded secrets or sensitive credentials
- [ ] **AI-Specific:** Protection against Prompt Injection (if applicable)
- [ ] **AI-Specific:** Outputs are sanitized before being used in critical sinks

### Performance

- [ ] No N+1 queries
- [ ] No unnecessary loops
- [ ] Appropriate caching
- [ ] Bundle size impact considered

### Code Quality

- [ ] Clear naming
- [ ] DRY - no duplicate code
- [ ] SOLID principles followed
- [ ] Appropriate abstraction level

### Testing

- [ ] Unit tests for new code
- [ ] Edge cases tested
- [ ] Tests readable and maintainable

### Documentation

- [ ] Complex logic commented
- [ ] Public APIs documented
- [ ] README updated if needed

## 🏗️ Architectural Review (Senior/Staff Level)

**Look beyond the lines of code. Look at the system.**

- [ ] **Failure Domains:** If this service dies, what else dies? (Cascading failures?)
- [ ] **Scalability:** Will this work with 10x data? 100x? (Unbounded lists, memory leaks)
- [ ] **Idempotency:** What happens if the message queue delivers this event twice?
- [ ] **Observability:** How will we know it's broken in production? (Logs, Metrics, Traces)
- [ ] **Migration Path:** How does this deploy? (Database locks, API versioning)

## 🔄 Operational Review

- [ ] **Feature Flags:** Is this behind a flag? Can we turn it off without a deploy?
- [ ] **Config:** Are secrets separated from config? Defaults sane?
- [ ] **Rollback:** Is this change backwards compatible? Can we revert safely?

## AI & LLM Review Patterns (2025)

### Logic & Hallucinations

- [ ] **Chain of Thought:** Does the logic follow a verifiable path?
- [ ] **Edge Cases:** Did the AI account for empty states, timeouts, and partial failures?
- [ ] **External State:** Is the code making safe assumptions about file systems or networks?

### Prompt Engineering Review

```markdown
// ❌ Vague prompt in code
const response = await ai.generate(userInput);

// ✅ Structured & Safe prompt
const response = await ai.generate({
  system: "You are a specialized parser...",
  input: sanitize(userInput),
  schema: ResponseSchema
});
```

## Anti-Patterns to Flag

```typescript
// ❌ Magic numbers
if (status === 3) { ... }

// ✅ Named constants
if (status === Status.ACTIVE) { ... }

// ❌ Deep nesting
if (a) { if (b) { if (c) { ... } } }

// ✅ Early returns
if (!a) return;
if (!b) return;
if (!c) return;
// do work

// ❌ Long functions (100+ lines)
// ✅ Small, focused functions

// ❌ any type
const data: any = ...

// ✅ Proper types
const data: UserData = ...
```

## Review Comments Guide

```
// Blocking issues use 🔴
🔴 BLOCKING: SQL injection vulnerability here

// Important suggestions use 🟡
🟡 SUGGESTION: Consider using useMemo for performance

// Minor nits use 🟢
🟢 NIT: Prefer const over let for immutable variable

// Questions use ❓
❓ QUESTION: What happens if user is null here?
```