Any way to specify the runtime type and validator when using TS defineProps?

[segevfiner]

When using <script setup> defineProps TypeScript syntax, if you specify any imported type as part of the definition, e.g.:

<script setup lang="ts">
import Foo from "./foo";

const props = defineProps<{
  foo: Foo,
}>();
</script>

Then the runtime type will be specified as null (any), is there any way to specify a type in such cases? and is there any syntax for specifying a validator when using the syntax? Yeah we get TypeScript checking when using this syntax so the runtime type checking might not be as important, but for libraries it might still be useful to include the runtime types and appropriate validators in case they are consumed by a non-TypeScript user.