Service Activator Generator

[GenerateServiceActivator] creates a typed ServiceActivator<TRequest, TResponse> factory.

[GenerateServiceActivator(typeof(InventoryReservationRequest), typeof(InventoryReservationResult), FactoryName = "Create", ActivatorName = "inventory-reservation-activator")]
public static partial class InventoryActivator
{
    [ServiceActivatorHandler]
    private static Message<InventoryReservationResult> Reserve(Message<InventoryReservationRequest> request, MessageContext context)
        => Message<InventoryReservationResult>.Create(new(request.Payload.Sku, true, "allocated"));
}

The generated factory has no parameters, so the activator can be registered directly in IServiceCollection and injected into application services.

Diagnostics:

• PKSVA001: host type must be partial.
• PKSVA002: exactly one service activator handler is required.
• PKSVA003: service activator handler signature is invalid.