Labrodev Exception

Exceptions: named unhappy paths, placed by origin

Part of the Labrodev playbook. The law for this component lives in the always-on labrodev-exception guideline (musts, must-nots); the per-file checklist is rules/exceptions.md. This skill holds the craft: anatomy, canonical templates, and edge cases.

An Exception is a named, explicit unhappy path — not a generic throw new \Exception('...'). Every thrown exception in a Labrodev project is its own final class, placed by where the failure originates, and constructed through a single static make() factory so the throw site reads as a sentence.

Placement law (origin, not consumer — the Domain/Shared/Infrastructure/Feature/Layer table) → labrodev-exception guideline.

Template: Domain exception

<?php

declare(strict_types=1);

namespace Core\Domain\Booking\Exceptions;

use Core\Domain\Booking\Models\Booking;
use RuntimeException;

final class BookingOverlapException extends RuntimeException
{
    private function __construct(string $message)
    {
        parent::__construct($message);
    }

    public static function make(Booking $booking): self
    {
        return new self(
            sprintf('Booking %s overlaps with an existing reservation.', $booking->uuid),
        );
    }
}

Throw site, inside a Domain Action or Service:

if (! BookingRule::canConfirm(booking: $booking)) {
    throw BookingOverlapException::make(booking: $booking);
}

Template: Infrastructure exception (wrapping a vendor failure)

<?php

declare(strict_types=1);

namespace Core\Infrastructure\Paddle\Exceptions;

use RuntimeException;
use Throwable;

final class PaddleChargeFailedException extends RuntimeException
{
    private function __construct(string $message, ?Throwable $previous = null)
    {
        parent::__construct($message, previous: $previous);
    }

    public static function make(string $reason, ?Throwable $previous = null): self
    {
        return new self(
            message: sprintf('Paddle charge failed: %s', $reason),
            previous: $previous,
        );
    }
}

The adapter catches the vendor SDK's exception and re-throws this one — the Domain never sees a vendor exception type → see the labrodev-infrastructure skill.

Template: Shared (generic) exception

<?php

declare(strict_types=1);

namespace Core\Shared\Exceptions;

final class InvalidUuidException extends \InvalidArgumentException
{
    private function __construct(string $message)
    {
        parent::__construct($message);
    }

    public static function make(string $value): self
    {
        return new self(sprintf('"%s" is not a valid UUID.', $value));
    }
}

Edge cases

• Multiple contextual arguments: make() follows the same named-argument rule as any multi-argument call — alphabetical order unless a stronger local convention exists → see the labrodev-naming skill.
• Wrapping an underlying exception: accept ?Throwable $previous in make() and pass it to parent::__construct(..., previous: $previous) so the original stack trace is preserved — do this whenever an Infrastructure or Shared exception wraps a caught SDK/library exception.
• Surfacing a domain exception to the user: never by converting it into ValidationException — that class is the Data validation layer's alone (→ labrodev-data). The exception stays a plain carrier of context; the delivery layer decides its user-facing shape (redirect + error toast, JSON error, status code) in Laravel's exception handler (bootstrap/app.php ->withExceptions(...) or a render() on an App-layer exception).
• HTTP rendering: an App/Exceptions exception may implement Laravel's render()/report() conventions or be mapped in the exception handler — that wiring is delivery-surface concern, not a reason to move the class out of App/Exceptions.
• Reused across Layers: if two Layers need the same exception, it is not Layer-specific — move it to the Core module (Domain/Shared/Feature) that actually detects the failure.
• Legacy zone: vendor/starter code under app/Http, app/Models, app/Actions/Fortify is exempt → see the labrodev-core skill.