svelte/test/runtime/samples/action-this/main.html

<button use:foo>{{x}}</button>

<script>
	export default {
		actions: {
			foo(node) {
				let x = 0;

				const handler = () => this.set({ x: x++ });

				node.addEventListener('click', handler);
				handler();

				return {
					destroy() {
						node.removeEventListener('click', handler);
					}
				};
			}
		},
	};
</script>