REslava.Result.FluentValidation 1.50.0

REslava.Result.FluentValidation

⚠️ Optional — migration bridge only.

This package is not needed for new projects. REslava.Result already includes full validation natively via [Validate] (DataAnnotations → Result<T>) and the Validation DSL (19 fluent rules). Install this package only if your team already uses FluentValidation validators and wants to keep them while adopting REslava.Result.

FluentValidation bridge for REslava.Result — keep your existing validators, get Result<T> and SmartEndpoints auto-injection for free.

What It Does

A migration bridge for teams with existing FluentValidation validators who are adopting REslava.Result. Decorate your request type with [FluentValidate] and the generator emits:

• Validate(IValidator<T> validator) — sync, runs validator.Validate(), returns Result<T>
• ValidateAsync(IValidator<T> validator, CancellationToken) — async variant

SmartEndpoints auto-injection — when a POST/PUT body parameter is decorated with [FluentValidate], the generated Minimal API lambda automatically adds IValidator<T> as a parameter and emits the validation guard block.

Quick Start

dotnet add package REslava.Result
dotnet add package REslava.Result.SourceGenerators
dotnet add package REslava.Result.FluentValidation   # ← bridge
dotnet add package FluentValidation                  # ← your existing validators

using REslava.Result.FluentValidation;
using FluentValidation;

// 1. Decorate the request type
[FluentValidate]
public record CreateOrderRequest(string CustomerId, decimal Amount);

// 2. Your existing FluentValidation validator — unchanged
public class CreateOrderRequestValidator : AbstractValidator<CreateOrderRequest>
{
    public CreateOrderRequestValidator()
    {
        RuleFor(x => x.CustomerId).NotEmpty();
        RuleFor(x => x.Amount).GreaterThan(0);
    }
}

// 3. Register in DI
builder.Services.AddScoped<IValidator<CreateOrderRequest>, CreateOrderRequestValidator>();

// 4. Manual usage
IValidator<CreateOrderRequest> validator = new CreateOrderRequestValidator();
Result<CreateOrderRequest> result = request.Validate(validator);

// 5. SmartEndpoints — validator auto-injected, no extra wiring needed
[AutoGenerateEndpoints(RoutePrefix = "/api/orders")]
public class OrderService
{
    public async Task<Result<Order>> CreateOrder(CreateOrderRequest req) => ...;
}
// app.MapOrderServiceEndpoints();  ← one line, validator injected automatically

Generated Code

For each type decorated with [FluentValidate]:

// namespace Generated.FluentValidationExtensions
public static class CreateOrderRequestFluentValidationExtensions
{
    public static Result<CreateOrderRequest> Validate(
        this CreateOrderRequest instance,
        IValidator<CreateOrderRequest> validator)
    {
        var result = validator.Validate(instance);
        if (result.IsValid)
            return Result<CreateOrderRequest>.Ok(instance);

        var errors = result.Errors
            .Select(e => (IError)new ValidationError(e.PropertyName, e.ErrorMessage))
            .ToList();
        return Result<CreateOrderRequest>.Fail(errors);
    }

    public static async Task<Result<CreateOrderRequest>> ValidateAsync(
        this CreateOrderRequest instance,
        IValidator<CreateOrderRequest> validator,
        CancellationToken cancellationToken = default) { ... }
}

SmartEndpoints Generated Lambda

ordersGroup.MapPost("/", async (
    CreateOrderRequest req,
    IValidator<CreateOrderRequest> reqValidator,   // ← auto-injected
    IOrderService svc,
    CancellationToken cancellationToken) =>
{
    var validation = req.Validate(reqValidator);   // ← auto-emitted
    if (!validation.IsSuccess) return validation.ToIResult();

    var result = await svc.CreateOrder(req, cancellationToken);
    return result.ToIResult();
});

Rules

• [FluentValidate] and [Validate] cannot both be applied to the same type (RESL1006 analyzer error)
• Users install FluentValidation (≥ 11.x) separately — this package ships no runtime binary
• Only POST/PUT body parameters trigger SmartEndpoints auto-injection (GET query params are skipped)

Requires

• REslava.Result (core library)
• REslava.Result.SourceGenerators (for SmartEndpoints)
• FluentValidation ≥ 11.x (installed by user)

Links

• GitHub Repository
• Changelog

MIT License | Works with any .NET project (netstandard2.0)