Kotlin SDK relies on deprecated kotlinx.datetime.Instant, making instantiating mock classes difficult

[salockhart]

Bug Report

Version

com.svix.kotlin:svix-kotlin:1.76.1

Platform

Darwin {name omitted} 24.6.0 Darwin Kernel Version 24.6.0: Mon Jul 14 11:30:29 PDT 2025; root:xnu-11417.140.69~1/RELEASE_ARM64_T6000 arm64

Description

The ApplicationOut class is defined as follows:

// This file is @generated
package com.svix.kotlin.models

import kotlinx.datetime.Instant
import kotlinx.serialization.Serializable

@Serializable
data class ApplicationOut(
    val createdAt: Instant,
    ...

Here, createdAt (and updatedAt, not visible) rely on the kotlinx.datetime.Instant class to define a datetime.

The kotlinx.datetime.Instant class is deprecated in favour of kotlin.time.Instant, which is functionally identical but unfortunately not able to be used to instantiate an ApplicationOut object.

This makes unit testing difficult - I can pull in the older version of org.jetbrains.kotlinx:kotlinx-datetime in order to get these classes, but they are incompatible with the rest of my codebase.

A possible solution may be to upgrade to org.jetbrains.kotlinx:kotlinx-datetime:0.7.1. In this version, the deprecated types have been aliased to the new ones.

[svix-jplatte]

Right, so the problem isn't directly that we use kotlinx-datetime, but that we use version 0.6.2 which unlike v0.7.1 is not compatible with the new kotline.time.Instant, correct? Like #2078, this seems like it requires a breaking change 😕
I'll let you know once we have decided on a way forward.

[salockhart]

Ah, yes, that's correct - it's less the library and more the specific version in use.

Thanks for considering this. I've got a workaround for the time being, but still would be interested in how this gets resolved.