AgentSkillsCN

acc-check-class-length

分析 PHP 代码中的类长度问题。检测超过 300 行的类、God 类的征兆、内聚度问题,以及 SRP 违规。

SKILL.md
--- frontmatter
name: acc-check-class-length
description: Analyzes PHP code for class length issues. Detects classes exceeding 300 lines, God class indicators, cohesion issues, SRP violations.

Class Length Check

Analyze PHP code for class size and cohesion issues.

Detection Thresholds

LinesClassification
1-100✅ Ideal
101-200⚠️ Acceptable
201-300🟡 Large - review needed
301-500🟠 Too large - split
501+🔴 God class - urgent refactoring

Detection Patterns

1. God Class Indicators

php
// GOD CLASS: Does everything
class OrderManager
{
    // Handles orders
    public function createOrder() {}
    public function updateOrder() {}
    public function cancelOrder() {}

    // Handles payments
    public function processPayment() {}
    public function refundPayment() {}

    // Handles shipping
    public function createShipment() {}
    public function trackShipment() {}

    // Handles inventory
    public function reserveStock() {}
    public function releaseStock() {}

    // Handles notifications
    public function sendOrderConfirmation() {}
    public function sendShippingNotification() {}

    // Handles reporting
    public function generateOrderReport() {}
    public function exportToExcel() {}

    // 50+ more methods...
}

// GOOD: Split by responsibility
class OrderService {}
class PaymentService {}
class ShippingService {}
class InventoryService {}
class NotificationService {}
class ReportingService {}

2. Low Cohesion Signs

php
// LOW COHESION: Methods don't use same properties
class UserService
{
    private $userRepository;
    private $emailService;
    private $paymentGateway;
    private $logService;
    private $cacheService;

    // User methods use $userRepository
    public function findUser() {}
    public function updateUser() {}

    // Email methods use $emailService (unrelated)
    public function sendEmail() {}
    public function validateEmail() {}

    // Payment methods use $paymentGateway (unrelated)
    public function processPayment() {}
    public function checkBalance() {}
}

// HIGH COHESION: All methods use same core dependencies
class UserService
{
    public function __construct(
        private UserRepository $userRepository,
        private PasswordHasher $hasher,
    ) {}

    public function findUser(int $id): User {}
    public function createUser(UserData $data): User {}
    public function updateUser(User $user, UserData $data): void {}
    public function changePassword(User $user, string $password): void {}
}

3. Too Many Dependencies

php
// TOO MANY DEPENDENCIES: Indicates SRP violation
class OrderProcessor
{
    public function __construct(
        private OrderRepository $orderRepository,
        private ProductRepository $productRepository,
        private UserRepository $userRepository,
        private PaymentGateway $paymentGateway,
        private ShippingService $shippingService,
        private InventoryService $inventoryService,
        private EmailService $emailService,
        private SmsService $smsService,
        private PushNotificationService $pushService,
        private LoggerInterface $logger,
        private CacheInterface $cache,
        private EventDispatcher $eventDispatcher,
        // 10+ more...
    ) {}
}

// GUIDELINE: Max 5-7 dependencies
class OrderProcessor
{
    public function __construct(
        private OrderRepository $orderRepository,
        private PaymentProcessor $paymentProcessor,
        private NotificationService $notificationService,
        private EventDispatcher $eventDispatcher,
    ) {}
}

4. Feature Envy

php
// FEATURE ENVY: Class manipulates other class's data extensively
class OrderPrinter
{
    public function print(Order $order): string
    {
        $output = "Order: " . $order->getId() . "\n";
        $output .= "Customer: " . $order->getCustomer()->getName() . "\n";
        $output .= "Address: " . $order->getCustomer()->getAddress()->getStreet() . "\n";
        $output .= "City: " . $order->getCustomer()->getAddress()->getCity() . "\n";

        $total = 0;
        foreach ($order->getItems() as $item) {
            $output .= $item->getProduct()->getName() . ": ";
            $output .= $item->getQuantity() . " x " . $item->getPrice() . "\n";
            $total += $item->getQuantity() * $item->getPrice();
        }
        // Many more lines accessing Order internals...
    }
}

// BETTER: Move logic to Order class
class Order
{
    public function format(): string
    {
        // Order knows how to format itself
    }
}

5. Too Many Public Methods

php
// TOO MANY PUBLIC METHODS: API surface too large
class UserService
{
    public function findById() {}
    public function findByEmail() {}
    public function findByPhone() {}
    public function findByUsername() {}
    public function findActive() {}
    public function findInactive() {}
    public function create() {}
    public function update() {}
    public function delete() {}
    public function activate() {}
    public function deactivate() {}
    public function ban() {}
    public function unban() {}
    public function verify() {}
    // 20+ more public methods
}

// BETTER: Split into focused classes
class UserFinder {}
class UserModifier {}
class UserStatusManager {}

Metrics

LCOM (Lack of Cohesion of Methods)

  • LCOM = 0: Perfect cohesion
  • LCOM < 0.5: Good cohesion
  • LCOM > 0.8: Poor cohesion

Class Complexity Indicators

  • Lines of code > 300
  • Methods > 20
  • Properties > 10
  • Dependencies > 7
  • Cyclomatic complexity > 50

Refactoring Strategies

Extract Class

php
// Before: One large class
class Order
{
    // Order data and methods (30 methods)
    // Pricing logic (10 methods)
    // Shipping logic (8 methods)
    // Notification logic (5 methods)
}

// After: Multiple focused classes
class Order {} // Core order data
class OrderPricing {} // Price calculation
class OrderShipping {} // Shipping logic
class OrderNotifier {} // Notifications

Introduce Domain Events

php
// Before: Class does everything
class OrderService
{
    public function complete(Order $order): void
    {
        $order->complete();
        $this->updateInventory($order);
        $this->sendEmail($order);
        $this->createInvoice($order);
        $this->notifyWarehouse($order);
    }
}

// After: Event-driven
class OrderService
{
    public function complete(Order $order): void
    {
        $order->complete();
        $this->eventDispatcher->dispatch(new OrderCompletedEvent($order));
    }
}

// Separate listeners handle each concern
class UpdateInventoryListener {}
class SendConfirmationEmailListener {}
class CreateInvoiceListener {}

Severity Classification

LinesSeverity
201-300🟡 Minor
301-500🟠 Major
501+🔴 Critical

Output Format

markdown
### Class Length: [ClassName] is too large

**Severity:** 🟠/🔴
**Location:** `file.php`
**Lines:** 450
**Methods:** 35
**Dependencies:** 12

**Issue:**
Class `OrderManager` is 450 lines with 35 methods, indicating multiple responsibilities.

**Responsibilities Detected:**
1. Order CRUD operations
2. Payment processing
3. Shipping management
4. Email notifications
5. Reporting

**Suggested Split:**

OrderService (100 lines) ├── OrderRepository PaymentProcessor (80 lines) ShippingManager (70 lines) OrderNotifier (50 lines) OrderReporter (60 lines)

code