Frontend Code Review

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.

Stick to the checklist below for every applicable file and mode.

Checklist

See references/code-quality.md, references/performance.md, for the living checklist split by category—treat it as the canonical set of rules to follow.

Flag each rule violation with urgency metadata so future reviewers can prioritize fixes.

Review Process

1. Open the relevant component/module. Gather lines that relate to class names, React Flow hooks, prop memoization, and styling. 2. For each rule in the review point, note where the code deviates and capture a representative snippet. 3. Compose the review section per the template below. Group violations first by Urgent flag, then by category order (Code Quality, Performance, Business Logic).

Required output

When invoked, the response must exactly follow one of the two templates:

Template A (any findings)

# Code review
Found <N> urgent issues need to be fixed:

## 1 <brief description of bug>
FilePath: <path> line <line>
<relevant code snippet or pointer>


### Suggested fix
<brief description of suggested fix>

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

Found <M> suggestions for improvement:

## 1 <brief description of suggestion>
FilePath: <path> line <line>
<relevant code snippet or pointer>


### Suggested fix
<brief description of suggested fix>

---

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

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

If the issue number is more than 10, summarize as "10+ urgent issues" or "10+ suggestions" and just output the first 10 issues.

Don't compress the blank lines between sections; keep them as-is for readability.

If you use Template A (i.e., there are issues to fix) and at least one issue requires code changes, append a brief follow-up question after the structured output asking whether the user wants you to apply the suggested fix(es). For example: "Would you like me to use the Suggested fix section to address these issues?"

Template B (no issues)

## Code review
No issues found.

Rule Catalog — Code Quality

Tailwind-first styling

IsUrgent: True Category: Code Quality

Description

Favor Tailwind CSS utility classes instead of adding new .module.css files unless a Tailwind combination cannot achieve the required styling. Keeping styles in Tailwind improves consistency and reduces maintenance overhead.

Update this file when adding, editing, or removing Code Quality rules so the catalog remains accurate.

Classname ordering for easy overrides

Description

When writing components, always place the incoming className prop after the component’s own class values so that downstream consumers can override or extend the styling. This keeps your component’s defaults but still lets external callers change or remove specific styles.

Example:

import { cn } from '@/utils/classnames'

const Button = ({ className }) => {
  return <div className={cn('bg-primary-600', className)}></div>
}

Rule Catalog — Performance

Complex prop memoization

IsUrgent: True Category: Performance

Description

Wrap complex prop values (objects, arrays, maps) in useMemo prior to passing them into child components to guarantee stable references and prevent unnecessary renders.

Update this file when adding, editing, or removing Performance rules so the catalog remains accurate.

Wrong:

<HeavyComp
    config={{
        provider: ...,
        detail: ...
    }}
/>

Right:

const config = useMemo(() => ({
    provider: ...,
    detail: ...
}), [provider, detail]);

<HeavyComp
    config={config}
/>