Hello, I'm using Ktor 2.0 and getting a weird error when deserializing the response body<T> us...

# ktor

[Alexandre Brown]

Hello, I'm using Ktor 2.0 and getting a weird error when deserializing the response body<T> using kotlinx serialization.

return response.body<MySerializableDataClass>() does not work I get an error "No transformation found: class io.ktor.utils.io.ByteBufferChannel -> class common.datasources.dtos.SerializablePredictV2ProtocolResponse"
Content-Type: application/json

But doing kotlinx.serialization.json.Json.decodeFromString(SerializablePredictV2ProtocolResponse.serializer(), response.bodyAsText()) works.

PS: I'm in a unit test environment, mocking the client engine as per documentation.

Any help is appreciated, thanks

[Alexandre Brown]

@Serializable
data class TestDataClass(
	val a: String
)

MockEngine {
   respond(
      content = Json.encodeToString(TestDataClass("hello")),
      status = HttpStatusCode.OK,
      headers = headersOf(HttpHeaders.ContentType, ContentType.Application.Json.toString())
   )
}

val httpClient = HttpClient(engine) {
		install(ContentNegotiation) {
			Json
		}
	}

val response = <http://httpClient.post|httpClient.post>("<http://localhost:8080/myurl>")

val testResult = response.body<TestDataClass>()

[Rustam Siniukov]

You need to use

install(ContentNegotiation) {
  json()
}

instead. Calling just Json doesn’t register serializer for ContentNegotiation

[Alexandre Brown]

@Rustam Siniukov Could you send me the import? Intellij does not seem to find it. I'm I missing a dependency?

[Rustam Siniukov]

do you have dependency on ktor-serialization-kotlinx-json ?

[Alexandre Brown]

I didnt, adding it now, just saw the migration guide for 2.0 where they mention it. Trying it now

[Alexandre Brown]

@Rustam Siniukov It works perfectly now, thanks a lot!