fix: whitespace completely removed in each loop

Author: paoloricciuti

.changeset/wise-lemons-wave.md

@@ -0,0 +1,5 @@
+---
+"svelte": patch
+---
+
+fix: whitespace completely removed in each loop

packages/svelte/src/internal/client/render.js

@@ -41,8 +41,12 @@ export function set_should_intro(value) {
  * @returns {void}
  */
 export function set_text(dom, value) {
+	// __nodeValue is ' ' by default...this means that if we are trying to set the value of a node
+	// that has never been updated but is already ' ' that node will never be set and it will remain
+	// an empty text node.
+
 	// @ts-expect-error need to add __value to patched prototype
-	const prev_node_value = dom.__nodeValue;
+	const prev_node_value = dom.nodeValue === dom.__nodeValue ? dom.__nodeValue : dom.nodeValue;
 	const next_node_value = stringify(value);
 	if (hydrating && dom.nodeValue === next_node_value) {
 		// In case of hydration don't reset the nodeValue as it's already correct.

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

@@ -0,0 +1,6 @@
+import { flushSync } from 'svelte';
+import { test } from '../../test';
+
+export default test({
+	html: `<p>space between</p>`
+});

packages/svelte/tests/runtime-runes/samples/each-whitespace/main.svelte

@@ -0,0 +1,7 @@
+<svelte:options runes />
+
+<p>
+	{#each ['space', ' ', 'between'] as word}
+		{word}
+	{/each}
+</p>