Command Generator

Generate CQRS-compliant Commands and Command Handlers with tests.

Command Characteristics

• Immutable: final readonly class
• Imperative naming: Verb + noun (CreateOrder, ConfirmPayment)
• Self-validating: Validates invariants in constructor
• Intent-revealing: Name describes what should happen
• Returns void or ID: Never returns data

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Generation Process

Step 1: Generate Command

Path: src/Application/{BoundedContext}/Command/

1. {Name}Command.php — Immutable command DTO

Step 2: Generate Handler

Path: src/Application/{BoundedContext}/Handler/

1. {Name}Handler.php — Command processor

Step 3: Generate Tests

Path: tests/Unit/Application/{BoundedContext}/

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File Placement

Component	Path
Command	src/Application/{BoundedContext}/Command/
Handler	src/Application/{BoundedContext}/Handler/
Unit Tests	tests/Unit/Application/{BoundedContext}/

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Command Naming Conventions

Action	Command Name	Returns
Create new	CreateOrderCommand	ID
Confirm/Approve	ConfirmOrderCommand	void
Cancel/Reject	CancelOrderCommand	void
Update property	UpdateShippingAddressCommand	void
Add child	AddOrderLineCommand	void
Remove child	RemoveOrderLineCommand	void

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Quick Template Reference

Command

final readonly class {Name}Command
{
    public function __construct(
        public {ValueObject} $id,
        public string $data
    ) {
        if (empty($data)) {
            throw new \InvalidArgumentException('Data is required');
        }
    }

    public static function fromArray(array $data): self
    {
        return new self(
            id: new {ValueObject}($data['id']),
            data: $data['data']
        );
    }
}

Handler (Update Flow)

final readonly class {Name}Handler
{
    public function __construct(
        private {Repository}Interface $repository,
        private EventDispatcherInterface $events
    ) {}

    public function __invoke({Name}Command $command): void
    {
        $aggregate = $this->repository->findById($command->id);

        if ($aggregate === null) {
            throw new NotFoundException($command->id);
        }

        $aggregate->doSomething($command->data);

        $this->repository->save($aggregate);

        foreach ($aggregate->releaseEvents() as $event) {
            $this->events->dispatch($event);
        }
    }
}

Handler (Create Flow)

public function __invoke(CreateCommand $command): AggregateId
{
    $aggregate = Aggregate::create(
        id: $this->repository->nextIdentity(),
        ...
    );

    $this->repository->save($aggregate);

    foreach ($aggregate->releaseEvents() as $event) {
        $this->events->dispatch($event);
    }

    return $aggregate->id();
}

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Anti-patterns to Avoid

Anti-pattern	Problem	Solution
Returning Data	Query through command	Use Query for reads
No Validation	Invalid commands	Validate in constructor
Business Logic	Handler has decisions	Delegate to aggregate
Missing Events	Events not dispatched	Always dispatch after save
Direct Persistence	Bypassing aggregate	Always use aggregate methods

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References

For complete PHP templates and examples, see:

• references/templates.md — Command, Handler, Test templates with patterns
• references/examples.md — CreateOrder, ConfirmOrder, CancelOrder examples and tests