Hi! Client question: Is `HttpResponseValidator`'s ...

# ktor

[sindrenm]

Hi! Client question: Is `HttpResponseValidator`'s handleResponseException supposed to also catch `io.ktor.client.call.NoTransformationFoundException`s? Cause it just seems to fall through in my case. I can see it catching other non-HTTP exceptions such as `kotlinx.serialization.MissingFieldException`s, for instance, and of course `io.ktor.client.features.ClientRequestException`s and `io.ktor.client.features.ServerResponseException`s. I'm on Ktor v1.6.7 on Android using the CIO engine.

[sindrenm]

Here's the client config, if that's helpful. It's not overly complex.

HttpClient(CIO) {
    install(Logging) {
        logger = Logger.ANDROID
        level = LogLevel.ALL
    }

    install(JsonFeature) {
        serializer = KotlinxSerializer(json)
    }

    HttpResponseValidator {
        handleResponseException {
            when (it) {
                // some specialized exception conversions ...
                // I would want/expect NoTransformationFoundExceptions as a potential case here
                is Exception -> throw ApiException.Other(it)
            }
        }
    }
}

[sindrenm]

I am able to force a NoTransformationFoundException by altering my JsonFeature installation:

install(JsonFeature) {
    serializer = KotlinxSerializer(json)
    acceptContentTypes = listOf(ContentType("application", "pdf"))
}

This is obviously not right, but I would still expect it to end up in the handleResponseException block.

[Aleksei Tirman [JB]]

The NoTransformationFoundException is thrown after executing the response pipeline but HttpResponseValidator’s exception handlers are called during execution of the response pipeline. So to catch it you can wrap a receive() call in try/catch .

[sindrenm]

I see. And I guess this is the receive() you're talking about:

https://api.ktor.io/older/1.6.7/ktor-client/ktor-client-core/io.ktor.client.call/r[…]=inline%20suspend%20fun%20%3CT%3E%20HttpResponse.receive():%20T

Is there a way I can generalize this call inside of my engine config? I'd want this try/catch around all network calls, so the client config seems like the right place to put it.

[sindrenm]

I guess what I'm looking for is a way to get a hold of the HttpResponse in some kind of feature in the engine config.

[Aleksei Tirman [JB]]

I don’t think it’s possible for NoTransformationFoundException

[sindrenm]

Gotcha. I also couldn't find anything. I'll look for another approach, then. Thanks a lot for the explanation, though! 😁