<https://youtrack.jetbrains.com/issue/KT-23449>

# javascript

[marcinmoskala]

https://youtrack.jetbrains.com/issue/KT-23449

[czyzby]

Without looking into the whole code: how are you deserializing the objects?

[czyzby]

If you're just trying to deserialize them into News, they will lose all information except for the date. You have to add additional type field and deserialize into the correct type based on that field.

[marcinmoskala]

Forgot to mention: I use Kotlin serialization, but I suspected this might be a problem so I repack all objects from this API:

// HACK: Serialization objects does not correspond correctly to real objects so we need to repack them all
    override suspend fun getNewsData(): NewsData {
        val str = httpGet(Endpoints.news)
        val parsed = json.parse<NewsData>(str)
        val articles = parsed.articles.map { Article(it.id, ArticleData(it.data.title, it.data.subtitle, it.data.imageUrl, it.data.url, it.data.occurrence), it.dateTime) }
        val infos = parsed.infos.map { Info(it.id, InfoData(it.data.title, it.data.imageUrl, it.data.description, it.data.sources, it.data.url, it.data.author, it.data.authorUrl), it.dateTime, it.accepted) }
        val puzzlers = parsed.puzzlers.map { Puzzler(it.id, PuzzlerData(it.data.title, it.data.level, it.data.question, it.data.answers, it.data.correctAnswer, it.data.explanation, it.data.author, it.data.authorUrl), it.dateTime, it.accepted) }
        val newsData = NewsData(articles, infos, puzzlers)
        return newsData
    }

[czyzby]

I think that might be the problem: val parsed = json.parse<NewsData>(str)

[marcinmoskala]

I am not junior developer. My passes articles, infos and puzzlers in separate properties

[czyzby]

OK, I take it back, read the whole thing.

[marcinmoskala]

But at this moment it works. getNewsData returns correct lists and all objects there are created in Kotlin/JS (as you can see above)

[marcinmoskala]

I also suspect that the reason of this problems might be in serialization, but if it takes place after this repacking then it must be also Kotlin/JS problem.

[czyzby]

Have you tried the checks after removing @Serializable?

[bashor]

@marcinmoskala does it work after “repack”?

[marcinmoskala]

No

[marcinmoskala]

@czyzby I need this because I pass this object through API and I need to deserialize

[bashor]

is it enough to build and run KotlinAcademyApp from master to reproduce?

[marcinmoskala]

Steps to reproduce: use news instead of newsData in showList function on NewsComponent

[czyzby]

I figured, just curious if @Serializable is causing the issue.

[czyzby]

I planned on using kotlinx-serialization in a toy project, this feels like a major bug.

[bashor]

@marcinmoskala would be nice if you could push a branch with code to reproduce

[marcinmoskala]

5 minutes

[bashor]

It would be even simpler/better if you could deploy it somewhere

[bashor]

if you don’t minify it

[marcinmoskala]

It is wired, but it works now

[marcinmoskala]

Maybe I haven't cleaned some caches before

[marcinmoskala]

I will test it more

[bashor]

Honestly, I think it’s some problem in kotlinx.serialization and I’d expected that “repacked” version works.

[bashor]

@sandwwraith is it the known bug?

[marcinmoskala]

It looks so. I must have had wrong code in caches. I have a problem with mutliplatform Kotlin/JS project what when I change something in common or in common-client then I must clean it, because just run doesn't use new code.

[sandwwraith]

Are you sure that you didn’t confuse kotlin.js.JSON with kotlinx.serialization.json.JSON? The former is known to produce “not fair” kotlin objects

[marcinmoskala]

I use https://github.com/Kotlin/kotlinx.serialization because it is multiplatform project