fix dynamic html bug

packages/svelte/src/internal/client/dom/blocks/html.js

@@ -1,26 +1,51 @@
 import { derived } from '../../reactivity/deriveds.js';
 import { render_effect } from '../../reactivity/effects.js';
 import { current_effect, get } from '../../runtime.js';
+import { is_array } from '../../utils.js';
 import { hydrate_nodes, hydrating } from '../hydration.js';
 import { create_fragment_from_html, remove } from '../reconciler.js';
 import { push_template_node } from '../template.js';
 
+/**
+ * @param {import('#client').Effect} effect
+ * @param {(Element | Comment | Text)[]} to_remove
+ * @returns {void}
+ */
+function remove_from_parent_effect(effect, to_remove) {
+	const dom = effect.dom;
+
+	if (is_array(dom)) {
+		for (let i = dom.length - 1; i >= 0; i--) {
+			if (to_remove.includes(dom[i])) {
+				dom.splice(i, 1);
+				break;
+			}
+		}
+	} else if (dom !== null && to_remove.includes(dom)) {
+		effect.dom = null;
+	}
+}
+
 /**
  * @param {Element | Text | Comment} anchor
  * @param {() => string} get_value
  * @param {boolean} svg
  * @returns {void}
  */
 export function html(anchor, get_value, svg) {
-	var effect = anchor.parentNode !== current_effect?.dom ? current_effect : null;
+	const parent_effect = anchor.parentNode !== current_effect?.dom ? current_effect : null;
 	let value = derived(get_value);
 
 	render_effect(() => {
-		var dom = html_to_dom(anchor, effect, get(value), svg);
-		effect = null;
+		var dom = html_to_dom(anchor, parent_effect, get(value), svg);
 
 		if (dom) {
-			return () => remove(dom);
+			return () => {
+				if (parent_effect !== null) {
+					remove_from_parent_effect(parent_effect, is_array(dom) ? dom : [dom]);
+				}
+				remove(dom);
+			};
 		}
 	});
 }

packages/svelte/tests/runtime-runes/samples/each-dynamic-html/_config.js

@@ -0,0 +1,39 @@
+import { flushSync } from '../../../../src/index-client';
+import { test } from '../../test';
+
+export default test({
+	html: `<button>add item</button><button>make span</button><button>reverse</button>`,
+
+	async test({ assert, target }) {
+		const [btn1, btn2, btn3] = target.querySelectorAll('button');
+
+		flushSync(() => {
+			btn1?.click();
+			btn1?.click();
+			btn1?.click();
+		});
+
+		assert.htmlEqual(
+			target.innerHTML,
+			`<button>add item</button><button>make span</button><button>reverse</button><div>Item 1</div><div>Item 2</div><div>Item 3</div>`
+		);
+
+		flushSync(() => {
+			btn2?.click();
+		});
+
+		assert.htmlEqual(
+			target.innerHTML,
+			`<button>add item</button><button>make span</button><button>reverse</button><span>Item 1</span><span>Item 2</span><span>Item 3</span>`
+		);
+
+		flushSync(() => {
+			btn3?.click();
+		});
+
+		assert.htmlEqual(
+			target.innerHTML,
+			`<button>add item</button><button>make span</button><button>reverse</button><span>Item 3</span><span>Item 2</span><span>Item 1</span>`
+		);
+	}
+});

packages/svelte/tests/runtime-runes/samples/each-dynamic-html/main.svelte

@@ -0,0 +1,30 @@
+<script>
+	let items = $state([]);
+
+	function add_item() {
+		items.push({
+			id: items.length,
+			text: 'Item ' + (items.length + 1),
+			html: '<div>Item ' + (items.length + 1) + '</div>',
+			dom: null,
+		})
+	}
+
+	function make_span() {
+		items.forEach(item => {
+			item.html = item.html.replace(/div/g, 'span')
+		})
+	}
+
+	function reverse() {
+		items.reverse();
+	}
+</script>
+
+<button on:click={add_item}>add item</button>
+<button on:click={make_span}>make span</button>
+<button on:click={reverse}>reverse</button>
+
+{#each items as item (item.id)}
+	{@html item.html}
+{/each}