FeatureSlice 1.0.4

FeatureSlice

FeatureSlice is an library aiming to help working with Vertical/Feature Slice Architecture.

FeatureSlices can be Handlers or Consumers, and have an Endpoint and/or FeatureToggle.

• Handlers are a InMemory Request handlers which produce an Response.
• Consumers are Message Consumers which take an Request and produce only Success or Error Result, they can be setup to use for example Azure ServiceBus to send Requests.
• Both of those can also be set to be reachable from API as Endpoints and/or have a FeatureToggle.

Those elements can be setup using two types of API:

FluentGenericBuilder

Endpoint

public sealed class ExampleEndpoint : FeatureSliceBuilder
    .WithEndpoint
    .Build<ExampleEndpoint>
{
    protected override Endpoint Endpoint => Map.Get("test", (int age) => 
    {
        return Results.Ok();
    });
}

Handler

public sealed class ExampleHandler : FeatureSliceBuilder
    .WithHandler<ExampleHandler.Request, ExampleHandler.Response, FromServices<Dependency1, Dependency2>>
    .Build<ExampleHandler>
{
    public record Request();
    public record Response();

    protected override async Task<Result<Response>> Handle(Request request, FromServices<Dependency1, Dependency2> dependencies)
    {
        var (dep1, dep2) = dependencies;

        await Task.CompletedTask;

        return new Response();
    }
}

Consumer

public sealed class ExampleConsumer : FeatureSliceBuilder
    .WithConsumer<ExampleConsumer.Request, FromServices<Dependency1, Dependency2>>
    .Build<ExampleConsumer>
{
    public record Request();

    protected override ConsumerName ConsumerName => new("ExampleConsumer");

    protected override Task<Result> Consume(Request request, FromServices<Dependency1, Dependency2> dependencies)
    {
        var (dep1, dep2) = dependencies;

        return Result.Success;
    }
}

Combination of Consumer with Endpoint, Handler with Endpoint and both with FeatureFlag

public sealed class ExampleConsumerWithEndpoint : FeatureSliceBuilder
    .WithFlag
    .WithEndpoint
    .WithConsumer<ExampleConsumerWithEndpoint.Request, FromServices<Dependency1, Dependency2>>
    .Build<ExampleConsumerWithEndpoint>
{
    public record Request();

    protected override ConsumerName ConsumerName => new("ExampleConsumerWithEndpoint");

    protected override Endpoint Endpoint => Map.Get("test", (int age) => 
    {
        return Results.Ok();
    });

    protected override Task<Result> Consume(Request request, FromServices<Dependency1, Dependency2> dependencies)
    {
        var (dep1, dep2) = dependencies;

        return Result.Success;
    }
}

Handlers and Consumers Expose Dispatch methods which allow them to be called from dependencies

public static void Use(
    IPublisher publisher,
    ExampleConsumer.Dispatch consumer,
    ExampleHandler.Dispatch handler,
    ExampleConsumerWithEndpoint.Dispatch consumerWithEndpoint)
{
    publisher.Dispatch(new ExampleConsumer.Request());
    consumer(new ExampleConsumer.Request());
    handler(new ExampleHandler.Request());
    consumerWithEndpoint(new ExampleConsumerWithEndpoint.Request());
}

Handlers and Consumers Expose Register for DI registration

public static void Register(IServiceCollection services, Messaging.ISetup setup, WebAppExtender hostExtender)
{
    ExampleEndpoint.Register(services, hostExtender);
    ExampleConsumer.Register(services, setup);
    ExampleHandler.Register(services, hostExtender);
    ExampleConsumerWithEndpoint.Register(services, setup, hostExtender);
}

Functional which needs more manual setup

Endpoint

public static class ExampleEndpoint
{
    public static void Register(IServiceCollection services, IHostExtender<WebApplication> extender)
    {
        services.FeatureSlice()
            .WithEndpoint(
                extender,
                Endpoint);
    }

    private static Endpoint Endpoint => Map.Get("test", (int age) => 
    {
        return Results.Ok();
    });
}

Handler

public sealed class ExampleHandler : Dispatchable<ExampleHandler, ExampleHandler.Request, Result<ExampleHandler.Response, Disabled>>
{
    public record Request();
    public record Response();

    public static void Register(IServiceCollection services, IHostExtender<WebApplication> extender)
    {
        services.FeatureSlice()
            .WithHandler<Dispatch, Request, Response, FromServices<Dependency1, Dependency2>>(
                Handle,
                handler => handler.Invoke);
    }

    private static async Task<Result<Response>> Handle(Request request, FromServices<Dependency1, Dependency2> dependencies)
    {
        var (dep1, dep2) = dependencies;

        await Task.CompletedTask;

        return new Response();
    }
}

Consumer

public static class ExampleConsumer
{
    public delegate Task<Result> Dispatch(Request request);

    public record Request();

    public static void Register(IServiceCollection services, Messaging.ISetup setup)
    {
        services.FeatureSlice()
            .WithConsumer<Dispatch, Request, FromServices<Dependency1, Dependency2>>(
                setup,
                new ("ExampleConsumer"),
                Consume,
                handler => handler.Invoke);
    }

    private static async Task<Result> Consume(Request request, FromServices<Dependency1, Dependency2> dependencies)
    {
        var (dep1, dep2) = dependencies;

        await Task.CompletedTask;

        return Result.Success;
    }
}

Combination of Consumer with Endpoint, Handler with Endpoint and both with FeatureFlag

public static class ExampleConsumerWithEndpoint
{
    public delegate Task<Result.Or<Disabled>> Dispatch(Request request);

    public record Request();

    public static void Register(IServiceCollection services, Messaging.ISetup setup, IHostExtender<WebApplication> extender)
    {
        services.FeatureSlice()
            .WithFlag("ExampleConsumerWithEndpoint")
            .WithEndpoint(
                extender,
                Endpoint)
            .WithConsumer<Dispatch, Request, FromServices<Dependency1, Dependency2>>(
                setup,
                new ("ExampleConsumerWithEndpoint"),
                Consume,
                handler => handler.Invoke);
    }

    private static Endpoint Endpoint => Map.Get("test", (int age) => 
    {
        return Results.Ok();
    });

    private static async Task<Result> Consume(Request request, FromServices<Dependency1, Dependency2> dependencies)
    {
        var (dep1, dep2) = dependencies;

        await Task.CompletedTask;

        return Result.Success;
    }
}

Handlers and Consumers need to have manually added Dispatch methods which allow them to be called from dependencies

public static void Use(
    IPublisher publisher,
    ExampleConsumer.Dispatch consumer,
    ExampleHandler.Dispatch handler,
    ExampleConsumerWithEndpoint.Dispatch consumerWithEndpoint)
{
    publisher.Dispatch(new ExampleConsumer.Request());
    consumer(new ExampleConsumer.Request());
    handler(new ExampleHandler.Request());
    consumerWithEndpoint(new ExampleConsumerWithEndpoint.Request());
}

Handlers and Consumers need to have manually added Register for DI registration

public static void Register(IServiceCollection services, Messaging.ISetup setup, WebAppExtender hostExtender)
{
    ExampleEndpoint.Register(services, hostExtender);
    ExampleConsumer.Register(services, setup);
    ExampleHandler.Register(services, hostExtender);
    ExampleConsumerWithEndpoint.Register(services, setup, hostExtender);
}

Samples

src/Samples

License

The code in this repo is licensed under the MIT license.