i have a test in which i feed `"{"type": "A", ...}"` into a `PolymorphicType.A.serializer()` it fai...

# serialization

[Nikky]

i have a test in which i feed "{"type": "A", ...}" into a PolymorphicType.A.serializer() it fails with a Unexpected JSON token at offset 11: Encountered an unknown key 'type'.
is there a way to skip that.. while also not adding type as a property to the class (because that creates other issue)
or using ignoreUnknownKeys = true because there could be other.. issues ?

oone way i found was to use

val a = Json.decodeFromString(PolymorphicType.serializer(), jsonString) as PolymorphicType.A

but that means that there is no way to use this.. except for encoding and decoding using the polymorphic types.. or you wil lose the type properties

[Eugen Martynov]

Try PolymorphicType.serializer() instead

[Eugen Martynov]

Or use ignoreUnknownKeys = true for your test

[Dominaezzz]

You don't need the type if you know the specific base class. So type will be an unknown key.
Sadly, kotlinx.serialization can't really be smart about this because a class could be implementing multiple interfaces, each with their own discriminator.

[Nikky]

this is for doing geojson in which the standard specifies that there should be a "type" key present
i guess i forgot to mention that requirement

[Nikky]

is there a way to delegate kotlinx-serialization to use override val type = "Point" and not conflict with it ?

[Dominaezzz]

Sadly no. I've tried to get around it before. You just have to use the base class.

[Nikky]

the tricky part is .. because of restrictions we have to make sure that jackson can also still serialize the damn thing.. (gladly no deserialization required)
i would be happy if we could jsut drop that whole stack ..

[Nikky]

so for now.. i use @SerialName and a @Transient val type: String to make it somehow work