ServiceStack + FluentValidation not triggering with ResolveService

Question

I'm using ServiceStack + FluentValidation v3.

I can post directly to the API and experience request validation, however, when calling from a resolved service instance in my MVC controller, no validation is triggered.

Using Fiddler, I POST the following:

POST /api/json/oneway/FieldSample HTTP/1.1
Content-Type: application/json
Content-Length: 66
Host: localhost:53185

{"Sample.Id":"2866246","Sample.SampleTime":"6/7/1950 12:00:00 PM"}

Response, as desired:

HTTP/1.1 400 Bad Request
Content-Type: application/json; charset=utf-8
Content-Length: 138
Connection: Close

{"responseStatus":{"errorCode":"LessThan","message":"TestTest","errors":[{"errorCode":"LessThan","fieldName":"Id","message":"TestTest"}]}}

From my MVC Controller:

using (var svc = AppHostBase.ResolveService<FieldSampleService>(System.Web.HttpContext.Current))
    {
        try { svc.Post(model.Sample); }
        catch (WebServiceException webEx)
        {
            return Json(new { Success = false }, "text/html");
        }
    }

No exception is thrown.

Manually creating an instance of the IValidator in the Service and throwing the exception DOES bubble the exception.

---

Why is the validation not triggering against requests originating from the AppHostBase.ResolveService?

Answer 1

I've made two discoveries here, though I'd like to see if anyone with more thorough knowledge of the source can confirm or disprove them.

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AppHostBase.ResolveService vs. JsonServiceClient

Changing my connection method to the following triggers validation.

using (var client = new JsonServiceClient(baseUri)) {
    client.Post(model.Sample);
}

The AppHostBase.ResolveService just returns an instance from the IoC container (like it should), but my assumption was that the instance would still use the same request filters/pipeline which is what triggers the validation. It makes sense that it's not the more I think about it, but it behavior certainly isn't obvious when considering the request filter validation method.

---

IReturnVoid prevents WebServiceException

Once I crossed that hurdle, I was having issues getting the FluentValidation error messages back. The docs show that a WebServiceException would be thrown containing the validation details, but I was getting a WebException. I finally realized my Request DTO was implementing IReturnVoid. This appears to determine which type of exception is thrown. Changing it to IReturn<any type> caused the WebServiceException to be thrown as desired.