Danom.Validation 2.0.0-beta6

Danom.Validation

One of the places the Result type really shines is input validation. It's a natural step in most workflows to validate input data before processing it, and the Result type is a great way to handle this. The Danom.Validation library provides an API for defining validation rules and checking input data against those rules, returning a Result<T, ResultErrors> that contains either the validated data or an error message.

Getting Started

Install the Danom.Validation NuGet package:

PM>  Install-Package Danom.Validation

Or using the dotnet CLI

dotnet add package Danom.Validation

Example

The example below demonstrates the functionality delivered from this slim API built on top of Danom.

using Danom;
using Danom.Validation;

public record Attendee(
    string Name,
    int Age,
    string Phone,
    Option<string> Email,
    Option<string> AlternateEmail,
    IEnumerable<string> Interests);

public sealed class AttendeeValidator : BaseValidator<Attendee>
{
    public AttendeeValidator()
    {
        Rule("Name", x => x.Name,
            Check.String.IsNotEmpty);

        Rule("Age", x => x.Age,
            Check.IsGreaterThan(0));

        Rule("Phone", x => x.Phone,
            Check.String.IsE164);

        Rule("Email", x => x.Email,
            Check.Required(Check.String.IsEmailAddress));

        Rule("AlternateEmail", x => x.AlternateEmail,
            Check.Optional(Check.String.IsEmailAddress));

        Rule("Interests", x => x.Interests,
            Check.Enumerable.ForEach(Check.String.IsLengthOrGreaterThan(2)));
    }
}

Validate<Attendee>
    .Using<AttendeeValidator>(new(
        Name: "John Doe",
        Age: 30,
        Phone: "+14055551234",
        Email: Option<string>.Some("john@doe.com"),
        AlternateEmail: Option<string>.None(),
        Interests: ["C#", "ASP.NET"]))
    .Match(
        ok: x => Console.WriteLine("Input is valid: {0}", x),
        error: e => Console.WriteLine("Input is invalid: {0}", e));

// or, if you don't care about the error messages use Result.ToOption() to
// flatten the result to an Option<T>
Validate<Attendee>
    .Using<AttendeeValidator>(new(
        Name: "",
        Age: -1,
        Phone: "123",
        Email: Option<string>.NoneValue,
        AlternateEmail: Option<string>.Some("invalid_email"),
        Interests: ["a"]))
    .ToOption()
    .Match(
        some: x => Console.WriteLine("Input is valid: {0}", x),
        none: () => Console.WriteLine("Input is invalid"));

Find a bug?

There's an issue for that.

License

Licensed under MIT.