FluentValidation Pipeline Integration

AstraFlow.FluentValidation automatically runs registered IValidator<TRequest> instances ahead of every response and void request handler, throwing AstraFlowValidationException with clean property groupings before business logic executes.

Installation & Setup

Install AstraFlow.FluentValidation alongside FluentValidation and AstraFlow.Mediator:

dotnet add package AstraFlow.FluentValidation

Register AddAstraFlowFluentValidation together with your FluentValidation validators and mediator:

using AstraFlow.FluentValidation;
using AstraFlow.Mediator;
using FluentValidation;

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddValidatorsFromAssemblyContaining<Program>();

builder.Services
    .AddAstraFlowMediator(validateRequestCoverage: true, typeof(Program))
    .AddAstraFlowFluentValidation(options =>
    {
        options.FailFast = false;
        options.LocalizeMessage = null;
    });

Defining Validators

Write standard FluentValidation AbstractValidator<T> classes for any IRequest or IRequest<TResponse> command:

using AstraFlow.Mediator;
using FluentValidation;

public sealed record CreateCustomerCommand(string Email, string DisplayName) : IRequest<Guid>;

public sealed class CreateCustomerValidator : AbstractValidator<CreateCustomerCommand>
{
    public CreateCustomerValidator()
    {
        RuleFor(x => x.Email).NotEmpty().EmailAddress();
        RuleFor(x => x.DisplayName).NotEmpty().MaximumLength(120);
    }
}

When sender.Send(new CreateCustomerCommand(...)) runs, AstraFlowValidationBehavior<TRequest, TResponse> (or AstraFlowVoidValidationBehavior<TRequest> for void commands) resolves every registered IValidator<TRequest>, runs ValidateAsync, and stops the pipeline with AstraFlowValidationException if any failures occur.

Configuration Options (AstraFlowValidationOptions)

Handling Validation Errors & ProblemDetails

Inspect grouped errors via AstraFlowValidationException.ToProblemDetailsErrors(), summarize validation metrics with AstraFlowValidationDiagnostics.CreateReport(ex.Errors), or let AstraFlowValidationProblemEndpointFilter convert exceptions directly into HTTP 400 ValidationProblem responses:

using AstraFlow.AspNetCore;

app.MapGroup("/api/customers")
    .AddEndpointFilter<AstraFlowValidationProblemEndpointFilter>()
    .MapAstraFlowSend<CreateCustomerCommand, Guid>("/");

Or map exceptions explicitly using AstraFlowProblemDetailsMapper.ToValidationProblemDetails(exception.ToProblemDetailsErrors()).

Related Guides

• Wire HTTP endpoints in ASP.NET Core Integration.
• Understand behavior execution order in Pipeline Behaviors & Exception Handling.
• Assert grouped validation payloads in Testing Harnesses.