I'm creating a serializable class exactly as the others but, Mark the class as @Serializable or provide the serializer explicitly

Question

I am trying to get a response from api and the Serialization it's not working, but it made the exactly the same with others data classes and they worked.

I am using ChangeFieldValueRequest data class as body to send with the request, as body, but i am receiving this message:

Failure(kotlinx.serialization.SerializationException: Serializer for class 'ChangeFieldValueRequest' is not found. Mark the class as @Serializable or provide the serializer explicitly.)

@Serializable
data class ChangeFieldValueRequest<T>(
    @SerialName("commercial_premise_id") val commercialPremiseId: Int,
    val field: String,
    val value: T
)

data class response

package com.quicktendr.mgmt.shared.domain

import kotlinx.serialization.Serializable

@Serializable
data class StatusResponse(
    val status: String,
    val error: String?
)

request:

suspend fun <T> updateLocalField(
        token: String, body: ChangeFieldValueRequest<T>
    ): StatusResponse {
        val request = handleError<StatusResponse> {
            httpClient.post("${baseUrl}api/management/updateLocalField") {
                this.body = body
                headers.append(HttpHeaders.ContentType, ContentType.Application.Json)
                headers.append("Authorization", "Bearer $token")
            }
        }
        when (request) {
            is ApiResult.Success -> {
                return request.value
            }
            is ApiResult.Error -> throw request.throwable
        }
    }


protected val httpClient: HttpClient = ServiceLocator.provideKtorHttpClient()
fun provideKtorHttpClient(): HttpClient {
        if(ktorHttpClient == null) {
            ktorHttpClient = HttpClient(generatePlatformHttpEngine()) {
                install(JsonFeature) {
                    serializer = KotlinxSerializer(Json {
                        encodeDefaults = true
                        ignoreUnknownKeys = true
                        isLenient = true
                    })
                    accept(ContentType.Application.Json)
                }
                install(Logging) {
                    logger = Logger.DEFAULT
                    level = LogLevel.ALL
                }
            }
        }

        return ktorHttpClient!!
    }

gradle cofiguration :

plugins {
    kotlin("multiplatform")
    kotlin("plugin.serialization")
...
}

   // kotlinx.serialization
    private const val ktxSerializationVersion = "1.0.1"

   // ktor
    private const val ktorVersion = "1.4.2"

    val ktxSerializationJson = "org.jetbrains.kotlinx:kotlinx-serialization-json:$ktxSerializationVersion"


 val ktorSerialization = "io.ktor:ktor-client-serialization:$ktorVersion"

I have to send this on body:

{
    "commercial_premise_id": 95,
    "field":"delivery_paused",
        "value": true
}

And the response body will be this:

{
  "status": "ok",
  "error": null
}

Answer 1

You may miss the plugin org.jetbrains.kotlin.plugin.serialization:

plugins {
    id("org.jetbrains.kotlin.plugin.serialization")
    ...
}