PHP

Name: PHP Conventions Description: General PHP coding standards covering strict typing, formatting, control flow, and error handling. Applies to all PHP files in the application. Compatible Agents: general-purpose, backend Tags: app/**/*.php, laravel, php, backend, typing, formatting, conventions

Rules

• Type hints on all parameters, return types, and properties — no untyped signatures
• Use union types or nullable (?Type) where needed
• Target PHPStan Level 9 compliance
• All code in English: variable names, comments, docblocks
• Foreign-language domain terms from external APIs are acceptable in DTOs where they match the API
• Run Laravel Pint before committing
• Avoid try-catch blocks — let exceptions bubble up to the framework's handler
• Only catch exceptions when you must react locally (retry logic, API fallback)
• Use early returns (guard clauses) to handle edge cases at the top of a method
• Never use else, elseif, or nested if blocks — invert the condition and return early
• Prefer immutability — use readonly properties where possible
• One class per file

Examples

// ✓ Early returns — guard clauses
public function process(Order $order): void
{
    if (! $order->isPaid()) {
        throw new UnpaidOrderException();
    }

    if (! $order->hasItems()) {
        throw new EmptyOrderException();
    }

    // Happy-path logic here
}

// ✗ Nested if/else — never do this
public function process(Order $order): void
{
    if ($order->isPaid()) {
        if ($order->hasItems()) {
            // deep logic
        } else {
            throw new EmptyOrderException();
        }
    } else {
        throw new UnpaidOrderException();
    }
}

// ✓ Fully typed class
class CreateInvoice
{
    public function __construct(
        private readonly GenerateInvoicePdf $generatePdf,
    ) {}

    public function execute(Order $order): Invoice
    {
        // implementation
    }
}

// ✓ Structured logging when catching
try {
    $this->externalService->call($data);
} catch (ServiceException $e) {
    Log::error('External service failed.', [
        'message' => $e->getMessage(),
        'data'    => $data,
    ]);
    throw $e;
}

Anti-Patterns

• Untyped function parameters or return types
• Using else or elseif — invert and return early instead
• Silently swallowing exceptions with empty catch blocks
• Using env() directly in application code (only in config files)
• Non-English variable names, comments, or method names
• Multiple classes in a single file

References

• PHPStan
• Laravel Pint
• Related: PHPStan/SKILL.md — static analysis compliance