ServiceScan.SourceGenerator

Source generator for services registrations inspired by Scrutor. Code generation allows to have AOT-compatible code, without an additional hit on startup performance due to runtime assembly scanning.

Installation

Add the NuGet Package to your project:

dotnet add package ServiceScan.SourceGenerator

Usage

ServiceScan generates a partial method implementation based on GenerateServiceRegistrations attribute. This attribute can be added to a partial method with IServiceCollection parameter. For example, based on the following partial method:

public static partial class ServicesExtensions
{
    [GenerateServiceRegistrations(AssignableTo = typeof(IMyService), Lifetime = ServiceLifetime.Scoped)]
    public static partial IServiceCollection AddServices(this IServiceCollection services);
}

ServiceScan will generate the following implementation:

public static partial class ServicesExtensions
{
    public static partial IServiceCollection AddServices(this IServiceCollection services)
    {
        return services
            .AddScoped<IMyService, ServiceImplementation1>()
            .AddScoped<IMyService, ServiceImplementation2>();
    }
}

The only thing left is to invoke this method on your IServiceCollection instance.

Examples

Register all FluentValidation validators

Unlike using FluentValidation.DependencyInjectionExtensions package, ServiceScan is AOT-compatible, and doesn't affect startup performance:

[GenerateServiceRegistrations(AssignableTo = typeof(IValidator<>), Lifetime = ServiceLifetime.Singleton)]
public static partial IServiceCollection AddValidators(this IServiceCollection services);

Add MediatR handlers

public static IServiceCollection AddMediatR(this IServiceCollection services)
{
    return services
        .AddTransient<IMediator, Mediator>()
        .AddMediatRHandlers();
}

[GenerateServiceRegistrations(AssignableTo = typeof(IRequestHandler<>), Lifetime = ServiceLifetime.Transient)]
[GenerateServiceRegistrations(AssignableTo = typeof(IRequestHandler<,>), Lifetime = ServiceLifetime.Transient)]
private static partial IServiceCollection AddMediatRHandlers(this IServiceCollection services);

It adds MediatR handlers, which would work for simple cases, although you might need to add other types like PipelineBehaviors or NotificationHandlers.

Add all repository types from your project based on name filter as their implemented interfaces:

[GenerateServiceRegistrations(
    TypeNameFilter = "*Repository",
    AsImplemetedInterfaces = true,
    Lifetime = ServiceLifetime.Scoped)]
private static partial IServiceCollection AddRepositories(this IServiceCollection services);

Parameters