Using as Mediator

INFO

This isn't what Wolverine was originally designed to do, but seems to be a popular use case for teams struggling with ASP.Net Core MVC Controller bloat.

For one reason or another, many teams will use Wolverine strictly as a "mediator" that is used to simplify MVC Controllers by offloading the actual request handling like so:

public class MediatorController : ControllerBase
{
    [HttpPost("/question")]
    public Task<Answer> Get(Question question, [FromServices] IMessageBus bus)
    {
        // All the real processing happens in Wolverine
        return bus.InvokeAsync<Answer>(question);
    }
}

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While that strategy works and doesn't require Wolverine.Http at all, there's an optimized Minimal API approach in Wolverine.HTTP to quickly build ASP.Net Core routes with Wolverine message handlers that bypasses some of the performance overhead of "classic mediator" usage.

The functionality is used from extension methods off of the ASP.Net Core WebApplication class used in bootstrapping:

// Functional equivalent to MapPost(pattern, (command, IMessageBus) => bus.Invoke(command))
app.MapPostToWolverine<HttpMessage1>("/wolverine");
app.MapPutToWolverine<HttpMessage2>("/wolverine");
app.MapDeleteToWolverine<HttpMessage3>("/wolverine");

// Functional equivalent to MapPost(pattern, (command, IMessageBus) => bus.Invoke<IResponse>(command))
app.MapPostToWolverine<CustomRequest, CustomResponse>("/wolverine/request");
app.MapDeleteToWolverine<CustomRequest, CustomResponse>("/wolverine/request");
app.MapPutToWolverine<CustomRequest, CustomResponse>("/wolverine/request");

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With this mechanism, Wolverine is able to optimize the runtime function for Minimal API by eliminating IoC service locations and some internal dictionary lookups compared to the "classic mediator" approach at the top.

This approach is potentially valuable for cases where you want to process a command or event message both through messaging or direct invocation and also want to execute the same message through an HTTP endpoint.