svelte/test/runtime/samples/dynamic-component-update-existing-instance/main.html

<svelte:component this="{ x ? Foo : Bar }" x='{x}'/>

<script>
	import Foo from './Foo.html';
	import Bar from './Bar.html';

	export default {
		data() {
			return { Foo, Bar };
		}
	};
</script>