Were there major changes to deserializing dynamic ...

# serialization

[Ryan Batchelder]

Were there major changes to deserializing dynamic objects from JS in Serialization 1.0.0-RC? I know the API has changed to merge the DynamicObjectParser into Json , but when trying to use .decodeFromDynamic() I'm getting

IllegalStateException: This serializer can be used only with Json format.Expected Decoder to be JsonDecoder, got class DynamicInput

The serializer in this case is a small data class annotated with @Serializable, and I've also tried using JsonObject.serializer() with the same results. How can I handle serializing a dynamic from a JS library into a Kotlin object in this case?

[Vsevolod Tolstopyatov [JB]]

It seems to be a bug, especially if it worked before. Could you please provide a reproducer?

[Vsevolod Tolstopyatov [JB]]

JsonObject.serializer() with the same results.

Are we talking about JsonObject serialization to dynamic here?

[Ryan Batchelder]

Opposite direction, trying to get a dynamic output from a JS library into a JsonObject.

[Vsevolod Tolstopyatov [JB]]

Was it working before 1.0.0-RC?

[Ryan Batchelder]

This is new code that I didn't have prior to updating, but I'd used the DynamicObjectParser in the past in 0.20.0 in a similar way and it worked fine.

I was trying to determine if there were any changes to how dynamic object decoding worked beyond the syntax changes that were auto-suggested. I can't find any documentation on decodeFromDynamic() to validate that I haven't missed something.

I have:

@Serializable
data class DecodedJwt(val header: JsonObject, val payload: JsonObject, val signature: String)

val payload = jsonwebtoken_decode(token, jsObject {complete = true; json = true} as DecodeOptions)
            val parsedPayload = Json{}.decodeFromDynamic<DecodedJwt>(payload)

where jsonwebtoken_decode is an external declaration that returns dynamic

[Ryan Batchelder]

The final line where .decodeFromDynamic<>() is called is where the error is being thrown from

[Ryan Batchelder]

I can step through in the IntelliJ Debugger and see that the dynamic object is coming back as expected

[Vsevolod Tolstopyatov [JB]]

Thanks, filed https://github.com/Kotlin/kotlinx.serialization/issues/1080

It doesn’t seem to be working prior to 1.0.0-RC either, but it’s still a bug that should be fixed. We only have syntactic, decodeFromDynamic actually invokes DynamicPbjectParser.parse under the hood

[Ryan Batchelder]

Thanks for your help and filing that! Good to know I wasn't just doing something wrong all along 🙂