fix

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

@@ -1,8 +1,6 @@
 /** @import { Effect, Source } from '#client' */
 import { noop } from '../../shared/utils.js';
-import { DIRTY } from '../constants.js';
 import { flushSync } from '../runtime.js';
-import { internal_set, mark_reactions } from './sources.js';
 
 /** @type {Set<Fork>} */
 const forks = new Set();

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

@@ -14,7 +14,8 @@ import {
 	derived_sources,
 	set_derived_sources,
 	check_dirtiness,
-	untracking
+	untracking,
+	queue_flush
 } from '../runtime.js';
 import { equals, safe_equals } from './equality.js';
 import {
@@ -221,6 +222,8 @@ export function internal_set(source, value) {
 
 			inspect_effects.clear();
 		}
+
+		queue_flush();
 	}
 
 	return value;

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

@@ -742,6 +742,24 @@ function flush_queued_effects(effects) {
  * @returns {void}
  */
 export function schedule_effect(signal) {
+	queue_flush();
+
+	var effect = (last_scheduled_effect = signal);
+
+	while (effect.parent !== null) {
+		effect = effect.parent;
+		var flags = effect.f;
+
+		if ((flags & (ROOT_EFFECT | BRANCH_EFFECT)) !== 0) {
+			if ((flags & CLEAN) === 0) return;
+			effect.f ^= CLEAN;
+		}
+	}
+
+	queued_root_effects.push(effect);
+}
+
+export function queue_flush() {
 	if (!is_flushing) {
 		is_flushing = true;
 		queueMicrotask(() => {
@@ -757,20 +775,6 @@ export function schedule_effect(signal) {
 			remove_active_fork();
 		});
 	}
-
-	var effect = (last_scheduled_effect = signal);
-
-	while (effect.parent !== null) {
-		effect = effect.parent;
-		var flags = effect.f;
-
-		if ((flags & (ROOT_EFFECT | BRANCH_EFFECT)) !== 0) {
-			if ((flags & CLEAN) === 0) return;
-			effect.f ^= CLEAN;
-		}
-	}
-
-	queued_root_effects.push(effect);
 }
 
 /**

packages/svelte/tests/runtime-runes/samples/async-error/_config.js

@@ -13,10 +13,14 @@ export default test({
 		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
-			'<button>step 1</button><button>step 2</button><button>step 3</button><p>oops!</p><button>reset</button>'
+			'<button>step 1</button><button>step 2</button><button>step 3</button><p>oops!</p><button data-id="reset">reset</button>'
 		);
 
 		flushSync(() => button2.click());
+
+		const reset = /** @type {HTMLButtonElement} */ (target.querySelector('[data-id="reset"]'));
+		flushSync(() => reset.click());
+
 		assert.htmlEqual(
 			target.innerHTML,
 			'<button>step 1</button><button>step 2</button><button>step 3</button><p>pending</p>'

packages/svelte/tests/runtime-runes/samples/async-error/main.svelte

@@ -15,6 +15,6 @@
 
 	{#snippet failed(error, reset)}
 		<p>{error.message}</p>
-		<button onclick={reset}>reset</button>
+		<button data-id="reset" onclick={reset}>reset</button>
 	{/snippet}
 </svelte:boundary>