fix

packages/svelte/src/compiler/phases/3-transform/client/visitors/template.js

@@ -1930,7 +1930,7 @@ export const template_visitors = {
 		}
 
 		if (node.name === 'noscript') {
-			context.state.template.push('<!>');
+			context.state.template.push('<noscript></noscript>');
 			return;
 		}
 		if (node.name === 'script') {

packages/svelte/src/internal/client/dev/hmr.js

@@ -18,7 +18,7 @@ export function hmr(source) {
 		/** @type {import("#client").Effect} */
 		let effect;
 
-		block(() => {
+		block(anchor, 0, () => {
 			const component = get(source);
 
 			if (effect) {

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

@@ -105,7 +105,7 @@ export function await_block(anchor, get_input, pending_fn, then_fn, catch_fn) {
 		}
 	}
 
-	var effect = block(() => {
+	var effect = block(anchor, 0, () => {
 		if (input === (input = get_input())) return;
 
 		if (is_promise(input)) {

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

@@ -122,7 +122,7 @@ export function each(anchor, flags, get_collection, get_key, render_fn, fallback
 	/** @type {import('#client').Effect | null} */
 	var fallback = null;
 
-	block(() => {
+	block(anchor, 0, () => {
 		var collection = get_collection();
 
 		var array = is_array(collection)

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

@@ -31,9 +31,7 @@ export function if_block(
 
 	var flags = elseif ? EFFECT_TRANSPARENT : 0;
 
-	block(() => {
-		assign_nodes(null, anchor); // TODO `block(anchor, () => {...})`
-
+	block(anchor, flags, () => {
 		if (condition === (condition = !!get_condition())) return;
 
 		/** Whether or not there was a hydration mismatch. Needs to be a `let` or else it isn't treeshaken out */
@@ -81,5 +79,5 @@ export function if_block(
 			// continue in hydration mode
 			set_hydrating(true);
 		}
-	}, flags);
+	});
 }

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

@@ -16,7 +16,7 @@ export function key_block(anchor, get_key, render_fn) {
 	/** @type {import('#client').Effect} */
 	let effect;
 
-	block(() => {
+	block(anchor, 0, () => {
 		if (safe_not_equal(key, (key = get_key()))) {
 			if (effect) {
 				pause_effect(effect);

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

@@ -21,7 +21,7 @@ export function snippet(get_snippet, node, ...args) {
 	/** @type {import('#client').Effect | null} */
 	var snippet_effect;
 
-	block(() => {
+	block(null, EFFECT_TRANSPARENT, () => {
 		if (snippet === (snippet = get_snippet())) return;
 
 		if (snippet_effect) {
@@ -32,7 +32,7 @@ export function snippet(get_snippet, node, ...args) {
 		if (snippet) {
 			snippet_effect = branch(() => /** @type {SnippetFn} */ (snippet)(node, ...args));
 		}
-	}, EFFECT_TRANSPARENT);
+	});
 }
 
 /**

packages/svelte/src/internal/client/dom/blocks/svelte-component.js

@@ -16,7 +16,7 @@ export function component(get_component, render_fn) {
 	/** @type {import('#client').Effect | null} */
 	let effect;
 
-	block(() => {
+	block(null, 0, () => {
 		if (component === (component = get_component())) return;
 
 		if (effect) {

packages/svelte/src/internal/client/dom/blocks/svelte-element.js

@@ -48,8 +48,7 @@ export function element(node, get_tag, is_svg, render_fn, get_namespace, locatio
 	 */
 	let each_item_block = current_each_item;
 
-	block(() => {
-		const element_effect = /** @type {import('#client').Effect} */ (current_effect);
+	block(anchor, 0, () => {
 		const next_tag = get_tag() || null;
 		const ns = get_namespace
 			? get_namespace()

packages/svelte/src/internal/client/dom/blocks/svelte-head.js

@@ -47,7 +47,7 @@ export function head(render_fn) {
 	}
 
 	try {
-		block(() => render_fn(anchor));
+		block(null, 0, () => render_fn(anchor));
 	} finally {
 		if (was_hydrating) {
 			set_hydrate_nodes(/** @type {import('#client').TemplateNode[]} */ (previous_hydrate_nodes));

packages/svelte/src/internal/client/reactivity/effects.js

@@ -299,11 +299,14 @@ export function template_effect(fn) {
 }
 
 /**
- * @param {(() => void)} fn
+ * @param {import('#client').TemplateNode | null} anchor
  * @param {number} flags
+ * @param {(() => void)} fn
  */
-export function block(fn, flags = 0) {
-	return create_effect(RENDER_EFFECT | BLOCK_EFFECT | flags, fn, true);
+export function block(anchor, flags, fn) {
+	const effect = create_effect(RENDER_EFFECT | BLOCK_EFFECT | flags, fn, true);
+	if (anchor !== null) effect.nodes = { start: null, end: anchor };
+	return effect;
 }
 
 /** @param {(() => void)} fn */