Tolitech.FluentValidation.Generators 1.0.0-preview.4

Tolitech.FluentValidation.Generators

Tolitech.FluentValidation.Generators is a C# source generator that automatically discovers and registers all FluentValidation validators in your project for dependency injection, without requiring manual registration or runtime reflection.

Key Features

• Automatic Discovery: Finds all classes inheriting from AbstractValidator<T> at compile time.
• Source Generation: Generates an extension method to register all discovered validators in the DI container.
• No Reflection: Eliminates the need for runtime scanning or manual registration.

How It Works

The generator scans your codebase for all non-abstract classes that inherit from FluentValidation.AbstractValidator<T>. It then generates an extension method AddGeneratedValidators for IServiceCollection, which registers each validator as a scoped service for its corresponding type.

Example

Suppose you have the following validator:

using FluentValidation;

public class PersonCommand
{
    public string FirstName { get; }
    public string LastName { get; }

    public PersonCommand(string firstName, string lastName)
    {
        FirstName = firstName;
        LastName = lastName;
    }
}

public class PersonCommandValidator : AbstractValidator<PersonCommand>
{
    public PersonCommandValidator()
    {
        RuleFor(x => x.FirstName).NotEmpty();
        RuleFor(x => x.LastName).NotEmpty();
    }
}

After building your project, the generator will produce an extension method like:

public static class FluentValidationServiceCollectionExtensions
{
    public static IServiceCollection AddGeneratedValidators(this IServiceCollection services)
    {
        services.AddScoped<IValidator<PersonCommand>, PersonCommandValidator>();
        // ...other discovered validators
        return services;
    }
}

Usage

1. Reference the Generator: Add a reference to the Tolitech.FluentValidation.Generators package in your project.

2. Call the Extension Method: In your application startup, register the generated validators:

   using Microsoft.Extensions.DependencyInjection;

   var services = new ServiceCollection();
   services.AddGeneratedValidators();

3. Resolve Validators: Validators are now available via DI:

   var provider = services.BuildServiceProvider();
   var validator = provider.GetService<IValidator<PersonCommand>>();

Technical Details

• The generator uses Roslyn APIs to analyze the syntax tree and semantic model at compile time.
• Only non-abstract classes directly inheriting from AbstractValidator<T> are registered.
• The generated code is placed in the Tolitech.FluentValidation.Generators namespace.
• The extension method is safe to call multiple times and can be combined with other service registrations.

Integration Testing

The project includes integration tests to ensure that validators are correctly registered and resolved, and that validation logic works as expected.