ai-code-reviewer

name	ai-code-reviewer
description	Agentic code review checklist for Unity C# scripts. Identifies SOLID violations, GC allocation anti-patterns, naked Singletons, missing null guards, and architectural smells before human review.
version	2.0.0
tags	["tooling","code-review","quality","architecture","automation","agentic","SOLID"]
argument-hint	action='review' target='Assets/Scripts/PlayerController.cs'
tier	2
requirements	{"unity_version":">=6.0","render_pipeline":"Any","dependencies":[]}
context_discovery	{"check_unity_version":false,"check_render_pipeline":false,"scan_manifest_for":[]}
performance_budget	{"gc_alloc_per_frame":"N/A — static analysis tool","max_update_cost":"N/A — static analysis tool"}
tdd_first	true
disable-model-invocation	false
user-invocable	true
allowed-tools	["read_resource","mcp_unityMCP_find_in_file","mcp_unityMCP_validate_script"]

AI Code Reviewer

Overview

An agentic code review pass that reads a C# script and checks it against a structured checklist of Unity-specific and general engineering quality criteria. It produces a structured report of CRITICAL, WARNING, and INFO findings, mimicking a senior engineer's code review — before the code reaches human review.

When to Use

• Use before committing a new feature to version control.
• Use after a code generation batch to verify generated code quality.
• Use during onboarding to enforce standards for new team members.
• ❌ Do NOT use as a replacement for human code review — use it to reduce the noise.

Review Checklist

🔴 CRITICAL — Must Fix Before Merge

ID	Check	Detection Pattern
C1	GetComponent called in Update()	Update.*GetComponent regex
C2	new List/Array allocation in Update()	Update.*new (List|Array|\[\])
C3	Find() or FindObjectOfType() in Update()	Update.*Find
C4	public field not [SerializeField] private	^public (int|float|string|bool)
C5	Naked Singleton (static instance, no DI)	static.*Instance.*=.*this
C6	Empty Unity messages (void Update() { })	void (Update|FixedUpdate)\(\) *\{ *\}
C7	Hardcoded magic string/number	"[a-z]+[A-Z]" in logic (non-const)

🟡 WARNING — Should Fix

ID	Check	Detection Pattern
W1	LINQ in hot path	\.Where\(|\.Select\(|\.FirstOrDefault in Update
W2	Missing null check after GetComponent	GetComponent not followed by if.*null
W3	string += in a loop	string.*\+=.* inside loop
W4	Class has >300 lines (SRP violation)	Line count
W5	Method has >30 lines (Single Responsibility)	Method line count
W6	No namespace declaration	File start ^using without namespace
W7	TODO comment left in code	//.*TODO

🔵 INFO — Consider Improving

ID	Check
I1	Missing XML doc comment on public methods
I2	Magic numbers not extracted to constants
I3	MonoBehaviour without [RequireComponent] for dependencies

Review Procedure

1. Read the file: Use read_resource or view_file to load the script.
2. Run each CRITICAL check using mcp_unityMCP_find_in_file with the detection regex.
3. Run WARNING checks similarly.
4. Compile Report: Format findings as the Report Format below.
5. Provide Fix Suggestions: For each CRITICAL, provide the corrected code snippet.

Report Format

📋 CODE REVIEW — PlayerController.cs
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
🔴 CRITICAL (2)
  [C1] Line 47: GetComponent<Rigidbody>() called inside Update()
       → Cache in Awake(): private Rigidbody _rb; → _rb = GetComponent<Rigidbody>();

  [C4] Line 12: public float Speed = 5f;
       → Change to: [SerializeField] private float _speed = 5f;

🟡 WARNING (1)
  [W6] No namespace found.
       → Add: namespace Game.Player { ... }

🔵 INFO (1)
  [I1] Public method Move() has no XML doc comment.

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Score: 6/10 — Needs fixes before merge

Few-Shot Examples

Example 1: Full Review Pass

User: "Review my PlayerController.cs before I commit it."

Agent:

1. Reads PlayerController.cs.
2. Runs find_in_file for Update.*GetComponent → finds line 47.
3. Runs find_in_file for ^public (int|float) → finds 3 violations.
4. Outputs structured report with fix snippets for each CRITICAL.

Example 2: Focused Check

User: "Check if there are any GC allocations in my Update methods."

Agent: Scans only for C1, C2, W1, W3 patterns and reports findings.

Best Practices

• ✅ Run this before @automated-unit-testing — type errors from bad patterns can cascade.
• ✅ Always provide the corrected code snippet alongside each CRITICAL finding.
• ✅ Score the file: 0 CRITICALs = merge-ready; any = block.
• ❌ NEVER auto-apply fixes without confirming with the user.

---

TDD Contract

⚠️ Legacy Skill — Refactor Pending Este skill NO tiene tests automatizados aún. El siguiente boilerplate es un punto de partida.

// Escribe estos tests ANTES de implementar:

// Test 1: should [expected behavior] when [condition]
[Test]
public void AiCodeReviewer_Should{ExpectedBehavior}_When{Condition}()
{{
    // Arrange
    // TODO: Setup test fixtures
    
    // Act
    // TODO: Execute system under test
    
    // Assert
    Assert.Fail("Not implemented — write test first");
}}

// Test 2: should handle [edge case]
[Test]
public void AiCodeReviewer_ShouldHandle{EdgeCase}()
{{
    // Arrange
    // TODO: Setup edge case scenario
    
    // Act
    // TODO: Execute
    
    // Assert
    Assert.Fail("Not implemented");
}}

// Test 3: should throw when [invalid input]
[Test]
public void AiCodeReviewer_ShouldThrow_When{InvalidInput}()
{{
    // Arrange
    var invalidInput = default;
    
    // Act & Assert
    Assert.Throws<Exception>(() => {{ /* execute */ }});
}}

Pasos para completar el TDD:

1. Descomenta los tests above
2. Implementa la funcionalidad mínima para que compile
3. Ejecuta los tests — deben fallar (RED)
4. Implementa la funcionalidad real
5. Verifica que los tests pasen (GREEN)
6. Refactorea manteniendo los tests verdes

---

Nota: Este skill fue marcado como tdd_first: false durante la auditoría v2.0.1. La sección TDD fue agregada automáticamente pero requiere customización manual para reflejar el comportamiento real del skill.

Related Skills

• @unified-style-guide — The standard this checker enforces
• @automated-unit-testing — Next step after a clean review
• @unity-compile-fixer — For compilation errors, not style smells
• @coreclr-gc-watchdog — For deep GC analysis beyond this checklist