RGamaFelix.ServiceResponse.FluentValidation 3.1.0

RGamaFelix.ServiceResponse.FluentValidation

Integration package that provides seamless conversion between FluentValidation results and ServiceResponse results.

Overview

This package extends the RGamaFelix.ServiceResponse library with helper methods to easily convert FluentValidation ValidationResult objects into strongly-typed service results, maintaining all validation error messages and providing consistent error handling.

Installation

  dotnet add package RGamaFelix.ServiceResponse.FluentValidation

Dependencies

• FluentValidation (12.0.0+)
• RGamaFelix.ServiceResponse (3.0.0+)
• .NET 9.0+

Features

• ✅ Direct conversion from ValidationResult to IServiceResultOf<T>
• ✅ Automatic error message extraction from validation failures
• ✅ Type-safe results with generic data types
• ✅ Null-safe design with comprehensive validation
• ✅ Consistent error handling with ResultTypeCode.InvalidData
• ✅ Extension method pattern for clean, fluent API

Usage

Basic Validation Conversion

using FluentValidation; 
using RGamaFelix.ServiceResponse;
using RGamaFelix.ServiceResponse.FluentValidation;

public class CreateUserRequest
{
    public string Name { get; set; }
    public string Email { get; set; }
}

public class CreateUserRequestValidator : AbstractValidator
{
    public CreateUserRequestValidator() 
    {
        RuleFor(x => x.Name)
            .NotEmpty().WithMessage("Name is required") 
            .MaximumLength(100).WithMessage("Name cannot exceed 100 characters");
        
        RuleFor(x => x.Email)
            .NotEmpty().WithMessage("Email is required")
            .EmailAddress().WithMessage("Email must be a valid email address");
    }
}

public class UserService
{
    public IServiceResultOfCreateUser(CreateUserRequest request)
    {
        var validator = new CreateUserRequestValidator();
        var validationResult = validator.Validate(request);
        if (!validationResult.IsValid)
        {
            // Convert validation errors to service result
            return validationResult.ToServiceResult<User>();
        }
        
        // Process valid request
        var user = new User { Name = request.Name, Email = request.Email };
        return ServiceResultOf<User>.Success(user, ResultTypeCode.Created);
    }
}

Error Handling

public async TaskCreateUser(CreateUserRequest request)
{
    var result = await userService.CreateUser(request);
    if (!result.IsSuccess)
    {
        // Validation errors are automatically included in the result
        return BadRequest(new
        {
            Errors = result.ErrorMessages,
            ResultCode = result.ResultTypeCode.Name
        });
    }
    
    return Created($"/api/users/{result.Data.Id}", result.Data);
}

Multiple Validation Steps

public IServiceResultOfProcessOrder(CreateOrderRequest request)
{
    // Validate basic order data
    var orderValidator = new CreateOrderRequestValidator(); 
    var orderValidation = orderValidator.Validate(request);
    if (!orderValidation.IsValid)
        return orderValidation.ToServiceResult<Order>();
    
    // Validate order items
    foreach (var item in request.Items)
    {
        var itemValidator = new OrderItemValidator();
        var itemValidation = itemValidator.Validate(item);
        if (!itemValidation.IsValid)
            return itemValidation.ToServiceResult<Order>();
    }
    
    // Process valid order
    var order = CreateOrder(request);
    return ServiceResultOf<Order>.Success(order, ResultTypeCode.Created);
}

API Reference

Extension Methods

ToServiceResult<T>(ValidationResult)

Converts a FluentValidation ValidationResult into a service result containing error messages.

Parameters:

• validationResult - The validation result to convert. Must not be null and must indicate a failed validation.

Returns:

• IServiceResultOf<T> - A service result with ResultTypeCode.InvalidData containing all validation error messages.

Exceptions:

• ArgumentNullException - Thrown when the validation result is null.
• InvalidOperationException - Thrown when the validation result indicates successful validation.

Example:

var validationResult = validator.Validate(model);
if (!validationResult.IsValid)
{
    return validationResult.ToServiceResult();
}

Error Message Processing

The extension method automatically:

1. Filters out null errors - Only processes validation errors with non-null error messages
2. Extracts error messages - Collects all ErrorMessage properties from failed validations
3. Handles empty collections - Returns an empty collection if no valid error messages are found
4. Sets appropriate result code - Always uses ResultTypeCode.InvalidData for validation failures

Integration with ASP.NET Core

When combined with the RestResponse package:

[ApiController]
[Route("api/[controller]")] 
public class UsersController : ControllerBase 
{
    [HttpPost]
        public async TaskCreateUser(CreateUserRequest request)
    {
        var result = await userService.CreateUser(request);
        // Automatic HTTP status code mapping:
        // ResultTypeCode.InvalidData -> 400 Bad Request
        // ResultTypeCode.Created -> 201 Created
        return result.ReturnServiceResult();
    }
}

Version Information

• Version: 3.0.0
• Target Framework: .NET 9.0
• Language: C# 13.0 (latest major)
• Nullable Reference Types: Enabled

License

This project is licensed under the MIT License - see the LICENSE file for details.

Repository

https://github.com/rgamafelix/ServiceResponse

Author

Rodrigo Gama Felix - rodrigo@gamafelix.com.br

Related Packages

• RGamaFelix.ServiceResponse - Core ServiceResponse library
• RGamaFelix.ServiceResponse.RestResponse
• ASP.NET Core integration