---
description: Comprehensive React/TypeScript frontend code review with optional parallel agents
name: review-frontend
disable-model-invocation: true
---

# Frontend Code Review

## Arguments

- `--parallel`: Spawn specialized subagents per technology area
- Path: Target directory (default: current working directory)

## Step 1: Identify Changed Files

```bash
git diff --name-only $(git merge-base HEAD main)..HEAD | grep -E '\.(tsx?|jsx?|mjs|cjs|css)$|^(remix|vite)\.config\.'
```

## Step 2: Detect Technologies

```bash
# Detect Remix v2 (any official adapter). When matched, the Remix-specific
# surface is delegated to beagle-react:review-remix-v2 in Step 4.
grep -E '"@remix-run/(react|node|cloudflare|deno|serve)"' package.json | head -3

# Detect React Flow
grep -r "@xyflow/react\|ReactFlow\|useNodesState" --include="*.tsx" -l | head -3

# Detect Zustand
grep -r "from 'zustand'\|create\(\(" --include="*.ts" --include="*.tsx" -l | head -3

# Detect Tailwind v4
grep -r "@theme\|@layer theme" --include="*.css" -l | head -3

# Check for test files
git diff --name-only $(git merge-base HEAD main)..HEAD | grep -E '\.test\.tsx?$'
```

## Step 3: Load Verification Protocol

Load `beagle-react:review-verification-protocol` before any substantive judgment on code.

**Pass before Step 5:** The skill is loaded (or its checklist is open in context). Do not classify severity or write findings until this gate clears.

## Step 4: Load Skills

Use the `Skill` tool to load each applicable skill (e.g., `Skill(skill: "beagle-react:react-router-code-review")`).

**Remix v2 branch (Step 2 detected `@remix-run/*` in package.json):**

- Load `beagle-react:review-remix-v2` — umbrella orchestrator that loads all six Remix v2 area review skills (routing, data-flow, forms, error-boundaries, perf/SSR, meta+sessions) with its own detection telemetry. Run it for the Remix-specific surface and consolidate its findings into this review's output.
- Do NOT also load `beagle-react:react-router-code-review` — Remix v2 sits on React Router v6 but routes through Remix's route module conventions, which `beagle-react:remix-v2-routing-review` (loaded via the umbrella) covers in that context.
- Still load `beagle-react:shadcn-code-review` and the conditional skills below — they're orthogonal to the Remix layer and apply to component/styling/state code regardless of router.

**Non-Remix branch (default):**

- `beagle-react:react-router-code-review`
- `beagle-react:shadcn-code-review`

**Conditionally load based on detection (both branches):**

| Condition | Skill |
|-----------|-------|
| @xyflow/react detected | `beagle-react:react-flow-code-review` |
| Zustand detected | `beagle-react:zustand-state` |
| Tailwind v4 detected | `beagle-react:tailwind-v4` |
| Test files changed | `beagle-react:vitest-testing` |

## Step 5: Review

**Sequential (default):**
1. Load applicable skills
2. Review React Router patterns first
3. Review shadcn/ui patterns
4. Review detected technology areas
5. Consolidate findings

**Parallel (--parallel flag):**
1. Detect all technologies upfront
2. Spawn one subagent per technology area with `Task` tool
3. Each agent loads its skill and reviews its domain
4. Wait for all agents
5. Consolidate findings

## Step 6: Verify Findings

Before reporting any issue:
1. Re-read the actual code (not just diff context)
2. For "unused" claims - did you search all references?
3. For "missing" claims - did you check framework/parent handling?
4. For syntax issues - did you verify against current version docs?
5. Remove any findings that are style preferences, not actual issues

**Pass before promoting to Critical/Major:** For that item, (2)–(4) are satisfied with a concrete artifact when applicable — e.g. opened file at `FILE:LINE`, grep/search output for references, or cited parent/framework code — not only diff context.

## Step 7: Review Convergence

### Single-Pass Completeness

You MUST report ALL issues across ALL categories (style, logic, types, tests, security, performance) in a single review pass. Do not hold back issues for later rounds.

Before submitting findings, ask yourself:
- "If all my recommended fixes are applied, will I find NEW issues in the fixed code?"
- "Am I requesting new code (tests, types, modules) that will itself need review?"

If yes to either: include those anticipated downstream issues NOW, in this review, so the author can address everything at once.

### Scope Rules

- Review ONLY the code in the diff and directly related existing code
- Do NOT request new features, test infrastructure, or architectural changes that didn't exist before the diff
- If test coverage is missing, flag it as ONE Minor issue ("Missing test coverage for X, Y, Z") — do NOT specify implementation details like mock libraries, behaviour extraction, or dependency injection patterns that would introduce substantial new code
- Typespecs, documentation, and naming issues are Minor unless they affect public API contracts
- Do NOT request adding new dependencies (e.g. Mox, testing libraries, linter plugins)

### Fix Complexity Budget

Fixes to existing code should be flagged at their real severity regardless of size.

However, requests for **net-new code that didn't exist before the diff** must be classified as Informational:
- Adding a new dependency (e.g. Mox, a linter plugin)
- Creating entirely new modules, files, or test suites
- Extracting new behaviours, protocols, or abstractions

These are improvement suggestions for the author to consider in future work, not review blockers.

### Iteration Policy

If this is a re-review after fixes were applied:
- ONLY verify that previously flagged issues were addressed correctly
- Do NOT introduce new findings unrelated to the previous review's issues
- Accept Minor/Nice-to-Have issues that weren't fixed — do not re-flag them
- The goal of re-review is VERIFICATION, not discovery

## Output Format

```markdown
## Review Summary

[1-2 sentence overview of findings]

## Issues

### Critical (Blocking)

1. [FILE:LINE] ISSUE_TITLE
   - Issue: Description of what's wrong
   - Why: Why this matters (bug, a11y, perf, security)
   - Fix: Specific recommended fix

### Major (Should Fix)

2. [FILE:LINE] ISSUE_TITLE
   - Issue: ...
   - Why: ...
   - Fix: ...

### Minor (Nice to Have)

N. [FILE:LINE] ISSUE_TITLE
   - Issue: ...
   - Why: ...
   - Fix: ...

### Informational (For Awareness)

N. [FILE:LINE] SUGGESTION_TITLE
   - Suggestion: ...
   - Rationale: ...

## Good Patterns

- [FILE:LINE] Pattern description (preserve this)

## Verdict

Ready: Yes | No | With fixes 1-N (Critical/Major only; Minor items are acceptable)
Rationale: [1-2 sentences]
```

## Post-Fix Verification

After fixes are applied, run:

```bash
npm run lint
npm run typecheck
npm run test
```

All checks must pass before approval.

## Gates

Advance in order; do not skip a **pass condition** by restating it informally.

1. **Scope recorded** — **Pass when:** You have the output of the Step 1 command (or an explicit substitute path list) naming what is in scope for this review.
2. **Protocol + branch skills loaded** — **Pass when:** `beagle-react:review-verification-protocol` and `beagle-react:shadcn-code-review` are loaded, **and** either (a) Step 2 found Remix v2 and `beagle-react:review-remix-v2` is loaded (without `beagle-react:react-router-code-review`), or (b) Step 2 found no Remix v2 and `beagle-react:react-router-code-review` is loaded — before first severity judgment.
3. **Conditional skills** — **Pass when:** For each Step 2 detection row (Remix v2, @xyflow/react, Zustand, Tailwind v4, test files), you either loaded the listed skill or recorded that detection was negative (which command returned no matches).
4. **Critical/Major evidence** — **Pass when:** Each such finding cites `FILE:LINE` that exists in the tree and meets the Step 6 pass rule for that finding type.
5. **Single output** — **Pass when:** The Issues section uses one continuous numbering sequence and this deliverable satisfies Step 7 single-pass completeness (no withheld issue types or rounds).

## Rules

- Load skills BEFORE reviewing (not after)
- Number every issue sequentially (1, 2, 3...)
- Include FILE:LINE for each issue
- Separate Issue/Why/Fix clearly
- Categorize by actual severity
- Don't assume Next.js patterns (no "use client")
- Run verification after fixes
- Report ALL issues in a single pass — do not hold back findings for later iterations
- Re-reviews verify previous fixes ONLY — no new discovery
- Requests for net-new code (new modules, dependencies, test suites) are Informational, not blocking
- The Verdict ignores Minor and Informational items — only Critical and Major block approval