Lukdrasil.Validation.Fluent 1.0.0

Lukdrasil.Validation

Lukdrasil.Validation is a .NET 8 library for functional and fluent validation, error handling, and result composition. It provides a robust, composable, and testable way to handle validation and error propagation in C# applications, including ASP.NET Core Minimal APIs. The solution consists of three projects:

• Validation: Core validation and result types.
• Validation.Fluent: Extensions for integration with FluentValidation.
• Validation.Tests: Unit tests for the validation logic.

Features

• Functional-style ValidationResult<T> for success/failure flows
• Composable error handling with ValidationError and ExtendedError
• Minimal API integration for ASP.NET Core
• FluentValidation support for seamless rule validation
• Async/await support for validation chains

Getting Started

Installation

Add the NuGet package to your project:

Core validation

Install-Package Lukdrasil.Validation -Version x.y.z

FluentValidation integration

Install-Package Lukdrasil.Validation.Fluent -Version x.y.z

Basic Usage

Creating Validation Results

using Lukdrasil.Result;

var success = ValidationResult<string>.Success("Valid value");
var error = new ValidationError(new Error.Error("ERR001", "Invalid value"));
var failure = ValidationResult<string>.Failure(error);
#### Composing Results
var result1 = ValidationResult<string>.Success("A");
var result2 = ValidationResult<string>.Failure(new ValidationError(new Error.Error("ERR002", "Error B")));
var combined = result1.And(result2); // Combines errors if any
#### Pattern Matching
var output = result1.Match(
    value => $"Success: {value}",
    err => $"Failure: {string.Join(", ", err.Errors.Select(e => e.Description))}"
);

Minimal API Integration

app.MapPost("/validate", (MyModel model) =>
{
    var result = ValidateModel(model);
    return result.ToHttpResult<MyModel, ValidationResult<MyModel>>();
});

FluentValidation Integration

using Lukdrasil.Validation.Fluent;
using FluentValidation;

public class MyModelValidator : AbstractValidator<MyModel>
{
    public MyModelValidator()
    {
        RuleFor(x => x.Name).NotEmpty();
    }
}

var result = ValidationResult<MyModel>.Success(new MyModel { Name = "" })
    .Validate<MyModel, MyModelValidator>();

if (!result.IsSuccess)
{
    // Handle validation errors
}

Testing

Unit tests are provided in the Validation.Tests project. Run them using your preferred test runner: dotnet test

Contributing

Contributions are welcome! Please open issues or submit pull requests for improvements and bug fixes.

License

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