chore: root effects should not have parents (#10950)

* chore: root effects should not have parents

* tune

* oops

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

Co-authored-by: Rich Harris <rich.harris@vercel.com>

---------

Co-authored-by: Rich Harris <rich.harris@vercel.com>

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

@@ -39,9 +39,10 @@ import { remove } from '../dom/reconciler.js';
  * @returns {import('#client').Effect}
  */
 function create_effect(type, fn, sync, init = true) {
+	var is_root = (type & ROOT_EFFECT) !== 0;
 	/** @type {import('#client').Effect} */
-	const effect = {
-		parent: current_effect,
+	var effect = {
+		parent: is_root ? null : current_effect,
 		dom: null,
 		deps: null,
 		f: type | DIRTY,
@@ -58,7 +59,7 @@ function create_effect(type, fn, sync, init = true) {
 		effect.l = current_effect.l + 1;
 	}
 
-	if (current_reaction !== null) {
+	if (current_reaction !== null && !is_root) {
 		if (current_reaction.effects === null) {
 			current_reaction.effects = [effect];
 		} else {
@@ -68,7 +69,7 @@ function create_effect(type, fn, sync, init = true) {
 
 	if (init) {
 		if (sync) {
-			const previously_flushing_effect = is_flushing_effect;
+			var previously_flushing_effect = is_flushing_effect;
 
 			try {
 				set_is_flushing_effect(true);

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

@@ -360,12 +360,7 @@ export function remove_reactions(signal, start_index) {
 export function destroy_children(signal) {
 	if (signal.effects) {
 		for (var i = 0; i < signal.effects.length; i += 1) {
-			var effect = signal.effects[i];
-
-			// TODO ideally root effects would be parentless
-			if ((effect.f & ROOT_EFFECT) === 0) {
-				destroy_effect(effect);
-			}
+			destroy_effect(signal.effects[i]);
 		}
 		signal.effects = null;
 	}