Describe the problem

Sorry about the goofy issue title. What I mean is this:

// src/lib/api.svelte.ts

export type Example = {
  value: number;
  doubled: number;
}

// Doesn't work! (returns a pojo)
export const getExampleRunes = (initialValue: number): Example => {
  const value = $state(initialValue);
  const doubled = $derived(value * 2);
  return {value, doubled}
}

// Works!
export class ExampleRunes implements Example {
  value = $state(0);
  doubled = $derived(this.value * 2)
  constructor(initialValue: number) {
    this.value = initialValue;
  }
}

Context: I was converting a function that created a hash of Svelte stores to runes, and missed the implication of the note on the docs page that says:

In this example, the compiler transforms done and text into get/set methods on the class prototype referencing private fields

So I spent a while wondering why the pojo returned from getExampleRunes above wasn't working.

Describe the proposed solution

Consider adding another sentence to that note, something like...

Important: You must define a class for this to work. Svelte can't do this for plain javascript objects.

Alternatives considered

I'm fine with using classes. It's just a documentation issue.

Importance

nice to have