hello all! I’ve just updated Ktor 2.0.0-beta-1 to...

# ktor

[cafonsomota]

hello all!

I’ve just updated Ktor 2.0.0-beta-1 to 2.0.2 (client), and I’ve noticed something strange happening:
• When a request fails (for instance, receiving a 403), I get the deserialized object as null instead of an exception
For example:

public suspend fun someCall(random: RandomObject): SomeObject = <http://client.post|client.post>(URL) {
  setBody(random)
}.body()

Previously, when I called this from:

public suspend fun invokeSomeCall(random: RandomObject, onSuccess: (SomeObject) -> Unit, onFailure: (SomeErrorObject) -> Unit) {
  try {
    val response = EntityManagerAPI.someCall(random)

    coroutineScope {
      onSuccess(response)
    }
  } catch (e: Exception) {
    coroutineScope {
      onFailure(processException(e))
    }
  }
}

And the server returns a 403, the deserialization of SomeObject would fail, and I’ll call onFailure. Now, with the new version, onSuccess is called and it’s deserialized with all the default values.

The rules that I’m using for Json on ContentNegotation are:

public val nonStrictJson: Json = Json {
  prettyPrint = true
  isLenient = true
  ignoreUnknownKeys = true
}

From my tests if I change isLenient to false, I get the previous behaviour; in any case I’m trying to understand what changed, or what I might be doing wrong?

Is there a better approach here? Perhaps, checking the status code before?

[Helio]

I’m not 100% if that’s the reason for your problem. But during the migration of the some of my services I experienced similar behaviour.

The solution on my case was configuring the HttpClient with expectSuccess = true.

[cafonsomota]

Wow! I wasn’t aware of this:

/**
 * Terminate [HttpClient.receivePipeline] if status code is not successful (>=300).
 */
public var expectSuccess: Boolean = false

[cafonsomota]

It worked! I wasn’t aware of this change:

https://github.com/ktorio/ktor/pull/2783

I wonder how many people will get their apps broken 😅.

@Helio was there some guideline that I might have missed during the migration?

[Helio]

https://ktor.io/docs/migrating-2.html#response-validation

[Helio]

I looked through this guide and there blogpost. https://blog.jetbrains.com/ktor/2022/04/11/ktor-2-0-released/

[cafonsomota]

Thank you!! I understood what I did wrong, I was using 2.0.0-beta1 that didn’t had the change, but it seems when 2.0.0 was released the default value has changed; it seems I was too early adopter 🙂

[Helio]

Glad it worked. =)