I've been debugging for quite a while now; turns o...

# javascript

[Bernhard]

I've been debugging for quite a while now; turns out there is a distinction between a JS object literal and a JS class for certain APIs (class properties get minified!); Handlebars for instance only works when you pass an object literal; is there a way to specify that in the type signature?

[Edoardo Luppi]

No, there is no way to create a "plain" object in non-external code.
Follow and upvote https://youtrack.jetbrains.com/issue/KT-56618

[Edoardo Luppi]

Also https://youtrack.jetbrains.com/issue/KT-17683 to prefer proper fields instead of getters.

[Bernhard]

I found that I can use @JsPlainObject with an external modifier to fix it, but I can not require this in the type signature

[Bernhard]

maybe Record<String, Any>?

[Edoardo Luppi]

What do you mean with

but I can not require this in the type signature

[Bernhard]

e.g. imagine a template function like:
renderTemplate('path/to/template.hbs', {key: 'test', 'key2': 1})

[Bernhard]

the second parameter is an object literal with the template context

[Bernhard]

typing the function like:

external fun renderTemplate(path: String, context: Any)

breaks when a class is passed as the context parameter

[Bernhard]

reason for that is that class attributes are minified

[Bernhard]

so instead of passing {'key': 'test'}, you get {'s_1': 'test'}

[Edoardo Luppi]

Yeah, if the type is as generic as Any or dynamic, there is no way to limit to plain objects.

[Edoardo Luppi]

Record might work, but it will limit the type of data you can pass too much imo

[Bernhard]

yeah, I think in this case Record is fine

[Bernhard]

can't require a record of records though, right?

[Bernhard]

would need to be a recursive type def

[Bernhard]

kinda like: Record String | Int

[Bernhard]

maybe using a map for that API works as well, thank you so far

[Bernhard]

not minifying attributes would also be great

[Edoardo Luppi]

KT-17683 would solve your issue btw.

[Bernhard]

already voted for it, thank you 🙂

[Bernhard]

I've created https://youtrack.jetbrains.com/issue/KT-70082/Kotlin-JS-interop-Difficulty-typing-functions-that-require-JS-objects as well since it's a related issue

[Bernhard]

@JsField could solve it but you're still left with the type safety issue