Agent skill
symfony-validation
Symfony validation — 3-layer validation strategy, constraints, DTO validation, domain invariants, validation groups, custom validators. Triggers on: validation, validator, constraint, DTO validation, input validation, invariant, assert, validation group
Install this agent skill to your Project
npx add-skill https://github.com/majiayu000/claude-skill-registry/tree/main/skills/other/other/symfony-validation
SKILL.md
Symfony Validation
You are an expert in multi-layer validation within Symfony hexagonal architecture.
When to Activate
- User needs input validation
- User asks about validation strategies
- User needs custom constraints
- User mentions DTO validation or domain invariants
3-Layer Validation Strategy
Layer 1: Presentation (Input Validation)
Where: Controllers, request listeners What: Format validation — is the input well-formed? How: Symfony Validator on request DTOs
// Request DTO with constraints
final readonly class CreateUserRequest
{
public function __construct(
#[Assert\NotBlank]
#[Assert\Email]
public string $email,
#[Assert\NotBlank]
#[Assert\Length(min: 2, max: 100)]
public string $name,
#[Assert\NotBlank]
#[Assert\Length(min: 8)]
#[Assert\Regex(pattern: '/[A-Z]/', message: 'Must contain uppercase')]
#[Assert\Regex(pattern: '/[0-9]/', message: 'Must contain a number')]
public string $password,
) {
}
}
Layer 2: Application (DTO/Command Validation)
Where: Command/Query classes, validated by Messenger middleware What: Business rule pre-checks — are the values acceptable? How: Symfony Validator constraints on command properties
final readonly class RegisterUser
{
public function __construct(
#[Assert\NotBlank]
#[Assert\Email]
public string $email,
#[Assert\NotBlank]
public string $name,
#[Assert\NotBlank]
public string $password,
) {
}
}
The validation middleware on the bus auto-validates before handler execution.
Layer 3: Domain (Invariants)
Where: Entity constructors, value objects, business methods What: Business invariants — is the operation valid in domain context? How: Pure PHP validation, throw domain exceptions
// Value object self-validates
final readonly class Email
{
public function __construct(public string $value)
{
if (!filter_var($value, FILTER_VALIDATE_EMAIL)) {
throw InvalidEmailException::forValue($value);
}
}
}
// Entity protects invariants
final class Order
{
public function cancel(string $reason): void
{
if ($this->status === OrderStatus::DELIVERED) {
throw CannotCancelDeliveredException::forOrder($this->id);
}
// ...
}
}
References
See references/ for detailed guides:
validation-layers.md— Full examples for each layer, custom constraints, groups
Recommended Agent Skills
Expand your agent's capabilities with these related and highly-rated skills.
majiayu000/claude-skill-registry
agent-ops-spec
Manage specification documents in .agent/specs/. Use when user provides requirements, acceptance criteria, or feature descriptions that need to be tracked and validated against implementation.
majiayu000/claude-skill-registry
agent-ops-state
Maintain .agent state files. Use at session start, after meaningful steps, and before concluding: read/update constitution/memory/focus/issues/baseline consistently.
majiayu000/claude-skill-registry
agent-ops-spec
Manage specification documents in .agent/specs/. Use when user provides requirements, acceptance criteria, or feature descriptions that need to be tracked and validated against implementation.
majiayu000/claude-skill-registry
agent-ops-testing
Test strategy, execution, and coverage analysis. Use when designing tests, running test suites, or analyzing test results beyond baseline checks.
majiayu000/claude-skill-registry
agent-ops-testing
Test strategy, execution, and coverage analysis. Use when designing tests, running test suites, or analyzing test results beyond baseline checks.
majiayu000/claude-skill-registry
agent-ops-state
Maintain .agent state files. Use at session start, after meaningful steps, and before concluding: read/update constitution/memory/focus/issues/baseline consistently.
Didn't find tool you were looking for?