svelte/test/runtime/samples/document-event/main.html

<svelte:document on:mouseenter='log("enter")' on:mouseleave='log("leave")'/>

<script>
	export default {
		data: () => ({ events: [] }),
		methods: {
			log(event) {
				this.set({ events: this.get().events.concat(event) });
			},
		},
	};
</script>