Service Layer Generator

GenerateServiceLayerOperationAttribute creates a typed ServiceLayerOperation<TRequest,TResponse> factory from a static partial host.

[GenerateServiceLayerOperation(typeof(RegisterCustomerRequest), typeof(CustomerRegistrationReceipt), FactoryName = "CreateOperation", OperationName = "register-customer")]
public static partial class GeneratedCustomerServiceLayer
{
    [ServiceLayerRule("email", "Email is required.", 10)]
    private static bool HasEmail(RegisterCustomerRequest request)
        => !string.IsNullOrWhiteSpace(request.Email);

    [ServiceLayerHandler]
    private static ValueTask<CustomerRegistrationReceipt> Handle(RegisterCustomerRequest request, CancellationToken cancellationToken)
        => new(new CustomerRegistrationReceipt(request.CustomerId, request.Email));
}

The generated factory is equivalent to:

ServiceLayerOperation<RegisterCustomerRequest, CustomerRegistrationReceipt>
    .Create("register-customer")
    .Require("email", "Email is required.", HasEmail)
    .Handle(Handle)
    .Build();

Rules are ordered by the order argument on [ServiceLayerRule].

Diagnostics:

• PKSL001: host type must be partial.
• PKSL002: exactly one [ServiceLayerHandler] method is required.
• PKSL003: handler must be static and return ValueTask<TResponse> from (TRequest, CancellationToken).
• PKSL004: rule must be static and return bool from TRequest.
• PKSL005: rule order values must be unique.