Hey peeps, I’m trying to use Kotlin-based enums and classes in JavaScript/TypeScript but these objec...

# multiplatform

[Sebastian]

Hey peeps, I’m trying to use Kotlin-based enums and classes in JavaScript/TypeScript but these objects have mangled fields (e.g. _category_0 instead of category) and lots of unneeded metadata (e.g. the enums’ hash code values) attached. Do I understand it correctly that I need write custom Serializers to turn these objects into more readable/simple JSON objects? Or what’s a good way to approach this? Perhaps there are some other annotations I need to check?

Example below: I’m trying to return a list of question objects with some fields (e.g. an enum-based type and a list of options).

[Sebastian]

Ideally, the result should be something like this instead:

[
  {
    "type": "options",
    "translationKey": "vegetables",
    "category": "diet",
    "options": [
      {
        "translationKey": "some_option",
        "values": {}
      },
      {
        "translationKey": "another_option",
        "values": {}
      }
    ]
  },
  {
    "type": "options",
    "translationKey": "organic",
    "category": "diet",
    "options": [
      {
        "translationKey": "some_option",
        "values": {}
      }
    ]
  },
  {
    "type": "number_input",
    "translationKey": "shortrangeflights",
    "category": "travel"
  }
]

[russhwolf]

If you're using the legacy compiler you probably need @JsName annotations. (Or @JsExport for the IR compiler, but if you were using that you'd get no output instead of mangled output when it's missing)

[Sebastian]

I’m using the IR compiler and added @JsExport to a top-level class that provides a method that returns a list of objects. I’ve also tried adding @JsName annotations to the fields but that didn’t change anything (I think the IR compiler doesn’t pick those up?).

[russhwolf]

You might need to @JsExport all the way down the hierarchy

[russhwolf]

I haven't actually done much here though. If that doesn't work you could also ask in #javascript

[Sebastian]

I’d love to use @JsExport everywhere but I’m using quite a few enums and it seems to be impossible to use @JsExport with enums?

[Sebastian]

Thanks for your help, @russhwolf! I’ll cross-post this in #javascript soon if I don’t find a solution in the meantime. ✌️

[Sebastian]

Update: Turns out that returning Array instead of List is very beneficial for the JS usage (as documented here). And with the proper @JsExport annotation on all classes that I want to use inside JS, I can also get the right field names. 🦜