DomainValidation.NET 1.0.0

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

        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.

var blog = Blog.Create("B1"); 

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

blog = Blog.Create("");

if (!blog.IsSuccess)
{
    Console.WriteLine(b.Error);
}

Project files explanations:

Error.cs file

This file contains a public record named Error with the following properties:

• Code: A string representing the error code.
• Message: A string representing the error message.
• LineNumber: An optional integer representing the line number where the error occurred. This property is set using the [CallerLineNumber] attribute.
• MemberName: An optional string representing the name of the member where the error occurred. This property is set using the [CallerMemberName] attribute.
• FilePath: An optional string representing the path of the file where the error occurred. This property is set using the [CallerFilePath] attribute.

This record also contains a static field named None which represents an empty error.

Result.cs file

This file contains a public class named Result with the following properties:

• IsSuccess: A boolean indicating whether the operation was successful or not.
• Error: An instance of the Error class representing any errors that occurred during the operation.

This class also contains several static methods for creating instances of this class:

• Success(): Creates a new instance of this class with IsSuccess set to true and Error set to Error.None.
• Success<TValue>(TValue value): Creates a new instance of this class with IsSuccess set to true, Error set to Error.None, and a value of type TValue.
• Failure(Error error): Creates a new instance of this class with IsSuccess set to false and an instance of the Error class representing any errors that occurred during the operation.
• Failure<TValue>(Error error, TValue? value = default): Creates a new instance of this class with IsSuccess set to false, an instance of the Error class representing any errors that occurred during the operation, and a value of type TValue.

ResultGeneric.cs file

This file contains a generic version of the Result class named Result<TValue>. This class inherits from the non-generic version of the class.

This class has an additional property named Value, which represents the result of a successful operation. If the operation was not successful, an exception is thrown.

This class also contains an implicit conversion operator from type TValue to type Result<TValue>.

P.S

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