visifo/smack-clause

SmackClause is a punchy, no-nonsense guard layer: it hits bad input fast, exits early, and leaves a clean trace of what failed, where, and why. The vibe is direct and a little aggressive, but the behavior is precise: stack small, composable rules, get strong default messages, and keep the happy path

dev-main 2026-04-03 08:38 UTC

Requires

• php: ^8.5

Requires (Dev)

• carthage-software/mago: ^1.16.0
• pestphp/pest: ^4.4.3
• phpstan/phpstan: ^2.1.44
• phpstan/phpstan-strict-rules: ^2.0.10
• rector/rector: ^2.3.9
• spatie/ray: ^1.47

MIT

• Sergej Tihonov

• clause
• guard
• visifo
• smack-clause
• smack
• guard clauses
• clauses
• early return

README

Fail fast. Speak clear. Stop bad input early.

SmackClause is a no-nonsense guard layer for PHP 8.5+. It hits bad input before it reaches your business logic, leaving a clean, structured trace of exactly what went wrong.

Why Smack?

• Direct Assertions: No "should be" or "must be" fluff. Just isInt(), isEmail(), min().
• Auto-Discovery: It knows your variable names. No more passing string labels manually.
• PHP 8.5 Native: Built for the future with property hooks, asymmetric visibility, and high-performance tokenization.
• Smart Nullability: Choose between a hard hit (that()) or a quiet pass (maybe()).

Installation

composer require visifo/smack-clause

Usage

The Hard Hit (Mandatory)

Smack::that() expects a value. If it's null or fails a rule, it smacks back.

Smack::that($email)->isString()->isEmail();
Smack::that($age)->isInt()->min(18);

The Quiet Pass (Optional)

Smack::maybe() allows nulls. If the value is there, it better be right.

Smack::maybe($bio)->isString()->max(200);

Hitting Collections

Smack::that($userIDs)->each()->isInt()->isPositive();

Allow Zero for Sign Checks

By default, isPositive() and isNegative() are strict (> 0 and < 0). Use allowZero() when you want zero to pass sign checks.

Smack::that($quantity)->isInt()->allowZero()->isPositive(); // allows 0 and positive ints
Smack::that($balance)->isInt()->allowZero()->isNegative(); // allows 0 and negative ints

Smack::that($price)->isFloat()->allowZero()->isPositive(); // allows 0.0 and positive floats
Smack::that($delta)->isFloat()->allowZero()->isNegative(); // allows 0.0 and negative floats

Custom Smacks

Extend the library with your own logic while keeping Smack::that(...)->... syntax.

use App\Smack\PlayerSmack;
use Visifo\SmackClause\Smack;

Smack::register(PlayerSmack::class);

Smack::that($player)
    ->isPlayer()
    ->isNotUn()
    ->isInPlayState();

You can register as many project-specific root methods as you need, one class at a time:

Smack::register(PlayerSmack::class);
Smack::register(VatSmack::class);

Use #[SmackMethod('...')] on the class and implement screenInto(...). Dynamic smack root methods do not accept arguments.

Option 1: Implement Smackable directly

use Visifo\SmackClause\Exceptions\SmackException;
use Visifo\SmackClause\Exceptions\Trace;
use Visifo\SmackClause\Extensions\SmackMethod;
use Visifo\SmackClause\Smackable;

#[SmackMethod('isVat')]
final readonly class VatSmack implements Smackable
{
    private function __construct(
        private VatId $vat,
        private Trace $trace,
    ) {}

    public static function screenInto(
        mixed $value,
        Trace $trace,
    ): self {
        if ($value instanceof VatId) {
            return new self($value, $trace);
        }

        throw SmackException::forExpectedType(VatId::class, $value, $trace);
    }

    public function isEu(): self
    {
        if ($this->vat->isEu()) {
            return $this;
        }

        throw SmackException::forConstraint('EU VAT ID', $this->vat, $this->trace);
    }
}

Option 2: Extend a typed smack (for method reuse)

If you extend ObjectSmack, always override screenInto(...) and call parent::__construct(...) to keep inherited object methods safe.

use Visifo\SmackClause\Exceptions\SmackException;
use Visifo\SmackClause\Exceptions\Trace;
use Visifo\SmackClause\Extensions\SmackMethod;
use Visifo\SmackClause\Types\ObjectSmack;

#[SmackMethod('isPlayer')]
final readonly class PlayerSmack extends ObjectSmack
{
    public function __construct(
        private GamePlayer $player,
        private Trace $trace,
    ) {
        parent::__construct($player, $trace);
    }

    public static function screenInto(mixed $value, Trace $trace): self
    {
        if ($value instanceof GamePlayer) {
            return new self($value, $trace);
        }

        throw SmackException::forExpectedType(GamePlayer::class, $value, $trace);
    }

    public function isNotUn(): self
    {
        if (! $this->player->isUn()) {
            return $this;
        }

        throw SmackException::forConstraint('not UN', $this->player, $this->trace);
    }
}

See tests/Fixtures/Smacks/PlayerSmack.php for a complete example.

IDE Helper

For dynamic custom methods (isPlayer(), isVat(), ...), generate a typed helper class for IDE/static tooling:

vendor/bin/smack-ide-helper

Available parameters:

• --root=<path>
  • Default: current working directory (getcwd()).
  • Purpose: project root used for composer.json, autoload, and output file location.
• --scan=<path>
  • Default: all autoload.psr-4 directories from <root>/composer.json.
  • Purpose: limit scanning to specific directory.
  • Notes: can be passed only once; when provided, it must point to a directory inside one of the root package's autoload.psr-4 directories.

This command generates _smack_ide_helper.php in your project root with a Visifo\\SmackClause\\IdeHelperSmack class that contains @method annotations for dynamic smack methods. Smack is linked to it via @mixin.

After generating, static tooling can understand calls like:

use Visifo\SmackClause\Smack;

Smack::that($player)
    ->isPlayer()
    ->isNotUn();

The generator is strict and fails if any registered smack class is invalid (missing #[SmackMethod('...')], duplicate method name, missing screenInto(...), inherited screenInto(...) without override, invalid class, etc.).

The Violation Report

When a check fails, SmackViolation (extends InvalidArgumentException) gives you the forensics:

• Path: The variable or nested key name.
• Value: What was actually received.
• Rule: Which assertion failed.

Changelog

Please see CHANGELOG for more information on what has changed recently.

Contributing

Please see CONTRIBUTING for details.

Branding & Tone Guide

TONE.md file ensures that anyone contributing to the project maintains the "Smack" vibe.

Security Vulnerabilities

Please review our security policy on how to report security vulnerabilities.

Credits

• Sergej Tihonov
• All Contributors

License

The MIT License (MIT). Please see License File for more information.