Setup to convert timestamp to DateTime in GraphQL

app-build.gradle

apollo {
    generateKotlinModels.set(true)
    customTypeMapping = [
            "timestamptz" : "org.threeten.bp.LocalDateTime"
    ]
}

dependencies { 
    implementation "org.threeten:threetenbp:1.5.1"
}

MyApolloClient.kt

/**
 * Timestamp delivered as string from API. This adapter takes care of encode / decode the same.
 */
private val timeStampAdapter = object : CustomTypeAdapter<LocalDateTime> {

    private val formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss.SSSSSSz")

    override fun decode(value: CustomTypeValue<*>): LocalDateTime {
        return try {
            LocalDateTime.parse(value.value.toString(), formatter)
        } catch (e: Exception) {
            throw RuntimeException("Cannot parse date: ${value.value}")
        }
    }

    override fun encode(value: LocalDateTime): CustomTypeValue<*> {
        return try {
            CustomTypeValue.GraphQLString(formatter.format(value))
        } catch (e: Exception) {
            throw RuntimeException("Cannot serialize  the date date: ${value}")
        }
    }
}


val apolloClient = ApolloClient
        .builder()
        .serverUrl("// url //")
        .addCustomTypeAdapter(CustomType.TIMESTAMPTZ, timeStampAdapter)
        .build()