Is there a way to define whether a property is required or not based on generic?

[PindaPixel]

For example for a dropdown list I'd want something like the following:

<script setup lang="ts" generic="T">
defineProps<{
    items: T[];
    keyField: T extends object ? keyof T : never;
}>();
</script>

[absidue]

I highly doubt it considering that as the types are used to generate runtime code, so it has to be either always required or always optional, as you can't have both at runtime.

[LinusBorg]

You can achieve something like this with a discriminated union, but it's a bit verbose and the type error is not very helpful:

https://play.vuejs.org/#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

[PindaPixel]

Yeah I figured type unions are the only way. I feel like a function syntax for defining props, emits, and the likes would make this easier through function overriding like with other frameworks but alas :(