DomainValidation.NET 1.1.0

Domain validation with returning result object

This project is an approach to domain validation with a result object. The Result class is used to handle errors and results in your application in a consistent and reliable way. If there is no validation issue and if the model is valid, then result.Value will return the value which is valid model and the result.IsSuccess is true. However, if something is wrong with domain validation, then result.IsSuccess is false and result.Error will hold error code and description.

Example:

Here we have a Blog class with a domain validation logic:

public class Blog
{
    private Blog(string title)
    {

        Title = title;
    }

    public static Result<Blog> Create(string title)
    {
        var errors = new List<Error>();

        if (string.IsNullOrEmpty(title))
        {
            return Result.Failure<Blog>(new Error("Error.Title.Empty", "Title is mandatory"));
        }

        if (title.Length < 3)
        {
            errors.Add(new Error("Error.Title", "The minimum title length is 3 character"));
        }

        if (title.Length > 40)
        {
            errors.Add(new Error("Error.Title.MaxLength", "The maximum title length is 40 character"));
        }

        if (errors.Any())
        {
            return Result.Failure<Blog>(errors.ToArray());
        }

        return new Blog(title);
    }

    public string Title { get; init; }
}

If we create an instance of Blog class with a valid title, then returned resule is successful with a new instance of Blog, but if it's not valid, then we will receive proper error message with detailed information about error.

if (blog.IsSuccess)
{
    Console.WriteLine(blog.Value.Title);
}

blog = Blog.Create("");

if (!blog.IsSuccess)
{
    foreach (var error in blog.Errors)
    {
        Console.WriteLine(error);
    }
}

blog = Blog.Create("B");

if (!blog.IsSuccess)
{
    foreach (var error in blog.Errors)
    {
        Console.WriteLine(error);
    }
}

P.S

This project has been inspired based on Domain Validation With .NET | Clean Architecture, DDD, .NET 6