fixes #14441

Author: dummdidumm

.changeset/breezy-insects-live.md

@@ -2,4 +2,4 @@
 'svelte': patch
 ---
 
-fix: show `:then` block for `null` value
+fix: show `:then` block for `null/undefined` value

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

@@ -42,7 +42,7 @@ export function await_block(node, get_input, pending_fn, then_fn, catch_fn) {
 	var component_function = DEV ? component_context?.function : null;
 
 	/** @type {V | Promise<V> | typeof UNINITIALIZED} */
-	var input;
+	var input = UNINITIALIZED;
 
 	/** @type {Effect | null} */
 	var pending_effect;

packages/svelte/tests/runtime-runes/samples/await-non-promise/_config.js

@@ -2,7 +2,6 @@ import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
-	solo: true,
 	compileOptions: {
 		dev: true
 	},
@@ -11,7 +10,7 @@ export default test({
 		const p = target.querySelector('p');
 		ok(p);
 
-		assert.htmlEqual(p.outerHTML, `<p>0</p>`);
+		assert.htmlEqual(p.outerHTML, `<p></p>`);
 
 		btn1.click();
 		flushSync();

packages/svelte/tests/runtime-runes/samples/await-non-promise/main.svelte

@@ -1,5 +1,5 @@
 <script>
-	let count = $state(0);
+	let count = $state();
 </script>
 
 <button onclick={() => count += 1}>increment</button>