Frontend Code Review

Intent

Use this skill whenever the user asks to review frontend code (especially .tsx, .ts, or .js files). Support two review modes:

1. Pending-change review – inspect staged/working-tree files slated for commit and flag checklist violations before submission.
2. File-targeted review – review the specific file(s) the user names and report the relevant checklist findings.

Checklist Categories

Code Quality

• Component follows single responsibility principle
• Props have proper TypeScript typing
• No unused imports or variables
• Consistent naming conventions
• Error boundaries in place where needed
• Proper use of React hooks (dependencies, cleanup)
• No direct DOM manipulation
• Accessibility attributes present (aria-*, role)

Performance

• Expensive computations memoized (useMemo, useCallback)
• Large lists use virtualization
• Images optimized and lazy-loaded
• No unnecessary re-renders (React.memo where appropriate)
• Bundle size considered (dynamic imports for large deps)
• No N+1 query patterns in data fetching

Business Logic

• Edge cases handled (empty states, loading, errors)
• User input validated
• Security considerations addressed (XSS, injection)
• Proper error messages displayed to user
• Business rules correctly implemented

Review Process

1. Open the relevant component/module
2. Gather lines that relate to:
   • Class names and styling
   • React hooks and state
   • Prop memoization
   • Event handlers
3. For each checklist item, note where the code deviates
4. Capture representative code snippets
5. Compose the review per the template below

Required Output

Template A (any findings)

# Code Review

Found <N> urgent issues need to be fixed:

## 1. <brief description of bug>
**FilePath:** `<path>` line `<line>`
```<language>
<relevant code snippet>

Suggested Fix

... (repeat for each urgent issue) ...

Found <M> suggestions for improvement:

1.

FilePath: <path> line <line>

<relevant code snippet>

Suggested Fix

... (repeat for each suggestion) ...

If there are no urgent issues, omit that section.
If there are no suggestions, omit that section.

If issue count exceeds 10, summarize as "10+ urgent issues" and output only the first 10.

**Follow-up:** If at least one issue requires code changes, ask:
> "Would you like me to apply the suggested fixes?"

### Template B (no issues)

Code Review

No issues found.

## Severity Guidelines

| Severity | Description | Example |
|----------|-------------|---------|
| 🔴 Urgent | Blocks release, security/data issue | XSS vulnerability, data leak |
| 🟠 Important | Should fix before merge | Missing error handling |
| 🟡 Suggestion | Code quality improvement | Naming convention, memoization |