Class ValidationBehavior<TMessage, TResponse>

Namespace

Trellis.Mediator

Assembly

Trellis.Mediator.dll

Unified validation stage of the Trellis Mediator pipeline. Runs the compile-time IValidate contract (when the message implements it) and every IMessageValidator<TMessage> registered for TMessage in DI, aggregates all Error.UnprocessableContent failures into a single response failure, and short-circuits the pipeline before the handler is invoked.

public sealed class ValidationBehavior<TMessage, TResponse> : IPipelineBehavior<TMessage, TResponse> where TMessage : IMessage where TResponse : IResult, IFailureFactory<TResponse>

Type Parameters

TMessage

The message type.

TResponse

The response type, constrained to IResult and IFailureFactory<TSelf> so the behavior can construct typed failures without reflection.

Inheritance

object

ValidationBehavior<TMessage, TResponse>

Implements

IPipelineBehavior<TMessage, TResponse>

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.ReferenceEquals(object, object)

object.ToString()

Extension Methods

MaybeExtensions.AsMaybe<T>(T)

MaybeExtensions.ToResult<TValue>(TValue)

NullableExtensions.ToResult<T>(T?, Func<Error>)

NullableExtensions.ToResult<T>(T?, Error)

AggregateTestMutator.ClearMaybeField<TEntity, TValue>(TEntity, Expression<Func<TEntity, Maybe<TValue>>>)

AggregateTestMutator.SetMaybeField<TEntity, TValue>(TEntity, Expression<Func<TEntity, Maybe<TValue>>>, TValue?)

Remarks

The behavior runs for every message — including messages that do not implement IValidate and have no registered IMessageValidator<TMessage> — in which case it is a no-op pass-through with one DI resolve and one type test.

Failure aggregation rules:

• Multiple Error.UnprocessableContent failures (from IValidate and any number of IMessageValidator<TMessage> instances) are merged into a single Error.UnprocessableContent whose Fields contains every reported FieldViolation and whose Rules contains every reported RuleViolation.
• An Error.UnprocessableContent with empty Fields AND empty Rules still short-circuits the handler: the original failure semantics from the validator are preserved, even when no violations are reported.
• A non-Error.UnprocessableContent failure (e.g., Error.Conflict, Error.Forbidden) returned by any validation source short-circuits the stage immediately and that failure is propagated as-is, with no further validators consulted.

Constructors

ValidationBehavior(IEnumerable<IMessageValidator<TMessage>>)

Unified validation stage of the Trellis Mediator pipeline. Runs the compile-time IValidate contract (when the message implements it) and every IMessageValidator<TMessage> registered for TMessage in DI, aggregates all Error.UnprocessableContent failures into a single response failure, and short-circuits the pipeline before the handler is invoked.

public ValidationBehavior(IEnumerable<IMessageValidator<TMessage>> validators)

Parameters

validators IEnumerable<IMessageValidator<TMessage>>

Remarks

The behavior runs for every message — including messages that do not implement IValidate and have no registered IMessageValidator<TMessage> — in which case it is a no-op pass-through with one DI resolve and one type test.

Failure aggregation rules:

• Multiple Error.UnprocessableContent failures (from IValidate and any number of IMessageValidator<TMessage> instances) are merged into a single Error.UnprocessableContent whose Fields contains every reported FieldViolation and whose Rules contains every reported RuleViolation.
• An Error.UnprocessableContent with empty Fields AND empty Rules still short-circuits the handler: the original failure semantics from the validator are preserved, even when no violations are reported.
• A non-Error.UnprocessableContent failure (e.g., Error.Conflict, Error.Forbidden) returned by any validation source short-circuits the stage immediately and that failure is propagated as-is, with no further validators consulted.

Methods

Handle(TMessage, MessageHandlerDelegate<TMessage, TResponse>, CancellationToken)

public ValueTask<TResponse> Handle(TMessage message, MessageHandlerDelegate<TMessage, TResponse> next, CancellationToken cancellationToken)

Parameters

message TMessage

next MessageHandlerDelegate<TMessage, TResponse>

cancellationToken CancellationToken

Returns

ValueTask<TResponse>