svelte/test/runtime/samples/transition-js-if-block-outro-timeout/main.html

{#if visible}
	<div out:fade style="opacity: 1;" ref:div>yes</div>
{/if}

<script>
	export default {
		transitions: {
			fade: function ( node, params ) {
				return {
					duration: 400,
					tick: t => {
						node.style.opacity = t;
					}
				};
			}
		}
	};
</script>