I want to use a generic type in a Svelte(Kit) component's props, and I found out there is this type T = $$Generic thing:
<script lang="ts">
import type { Writable } from "svelte/store";
type T = $$Generic;
export let store: Writable<T[]>;
</script>
While that is great, I do need slightly more information than that: I require that the T has a property id. Normally I'd do something like this:
export type WithId = { id: number };
function foo<T extends WithId>(property: T) { ... }
How can I do something similar for Svelte component props?
Edit: The design was changed, generics should now be defined as an attribute which uses the regular extends keyword:
<script lang="ts" generics="T extends { id: number }">
You can specify the type it extends like this:
type T = $$Generic<{ id: number }>;
You can also use type or interface names, though if you define them within a component, you might have to place them in the module script, i.e. something like this:
<script lang="ts" context="module">
interface WithId { id: number }
</script>
<script lang="ts">
export let store: Writable<T[]>;
type T = $$Generic<WithId>;
</script>