ValiCraft 1.0.5

ValiCraft

A high-performance validation library for .NET that uses source generators to craft fast, allocation-free validation logic at compile time.

Why ValiCraft?

ValiCraft takes a fundamentally different approach to validation. Instead of interpreting validation rules at runtime, ValiCraft uses C# source generators to analyze your validator definitions at compile time and generate highly optimized, native validation code.

Key Benefits:

• 🚀 Extreme Performance — Validation executes in nanoseconds with zero allocations for valid models
• 📦 Zero Runtime Overhead — No reflection, no expression tree compilation, no runtime code generation
• 🔧 Compile-Time Safety — Validation logic is generated and type-checked at build time
• ✨ Clean API — Fluent builder pattern with IntelliSense support
• 🔌 DI Ready — Source-generated dependency injection with no reflection

Quick Start

1. Define Your Model

public class User
{
    public required string Username { get; set; }
    public string? Email { get; set; }
    public int Age { get; set; }
}

2. Create a Validator

using ValiCraft;
using ValiCraft.Attributes;

[GenerateValidator]
public partial class UserValidator : Validator<User>
{
    protected override void DefineRules(IValidationRuleBuilder<User> builder)
    {
        builder.Ensure(x => x.Username)
            .IsNotNullOrWhiteSpace()
            .HasMinLength(3)
            .HasMaxLength(50);

        builder.Ensure(x => x.Email)
            .IsNotNullOrWhiteSpace()
            .IsEmailAddress();

        builder.Ensure(x => x.Age)
            .IsGreaterOrEqualThan(0)
            .IsLessThan(150);
    }
}

The [GenerateValidator] attribute tells the source generator to create the validation implementation. The partial keyword is required to allow the generated code to extend your type.

Optional Configuration:

The [GenerateValidator] attribute supports the following properties:

• IncludeDefaultMetadata (default: false) — When true, includes default metadata (RequestType and ValidationCount) in the generated ValidationErrors object.

[GenerateValidator(IncludeDefaultMetadata = true)]
public partial class UserValidator : Validator<User>
{
    // ...
}

3. Run Validation

var validator = new UserValidator();
var user = new User { Username = "john", Email = "john@example.com", Age = 30 };

ValidationErrors? result = validator.Validate(user);

if (result is null)
{
    Console.WriteLine("User is valid!");
}
else
{
    Console.WriteLine($"Validation failed: {result.Message}");
}

Performance

ValiCraft delivers exceptional performance compared to traditional validation libraries. Here's a snapshot (full benchmarks in docs/performance.md):

Simple Validation - Valid Model

Simple Validation - Invalid Model

Note: ValiCraft validators have near-zero instantiation cost (~3ns, 24B for the class instance) because the source generator produces validation logic that requires no runtime initialization. See full benchmark results for collection, complex, and instantiation benchmarks.

Installation

dotnet add package ValiCraft

Documentation

Diagnostics

ValiCraft emits helpful compiler diagnostics when there are issues with your validators:

These diagnostics appear directly in your IDE with exact source locations.

Requirements

• .NET 8.0 or higher
• C# 12 or higher

License

MIT — see LICENSE for details.

Contributing

Contributions are welcome! Please see CONTRIBUTING.md for guidelines.