chore: tweak effect self invalidation logic (#15275)

Also make sure events dispatched via transition/animation logic runs outside event context

Related to #15262

Author: trueadm

.changeset/rare-hounds-wave.md

@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+chore: tweak effect self invalidation logic, run transition dispatches without reactive context

packages/svelte/src/internal/client/dom/elements/transitions.js

@@ -14,14 +14,17 @@ import { current_each_item } from '../blocks/each.js';
 import { TRANSITION_GLOBAL, TRANSITION_IN, TRANSITION_OUT } from '../../../../constants.js';
 import { BLOCK_EFFECT, EFFECT_RAN, EFFECT_TRANSPARENT } from '../../constants.js';
 import { queue_micro_task } from '../task.js';
+import { without_reactive_context } from './bindings/shared.js';
 
 /**
  * @param {Element} element
  * @param {'introstart' | 'introend' | 'outrostart' | 'outroend'} type
  * @returns {void}
  */
 function dispatch_event(element, type) {
-	element.dispatchEvent(new CustomEvent(type));
+	without_reactive_context(() => {
+		element.dispatchEvent(new CustomEvent(type));
+	});
 }
 
 /**

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

@@ -370,22 +370,18 @@ export function handle_error(error, effect, previous_effect, component_context)
 /**
  * @param {Value} signal
  * @param {Effect} effect
- * @param {number} [depth]
+ * @param {boolean} [root]
  */
-function schedule_possible_effect_self_invalidation(signal, effect, depth = 0) {
+function schedule_possible_effect_self_invalidation(signal, effect, root = true) {
 	var reactions = signal.reactions;
 	if (reactions === null) return;
 
 	for (var i = 0; i < reactions.length; i++) {
 		var reaction = reactions[i];
 		if ((reaction.f & DERIVED) !== 0) {
-			schedule_possible_effect_self_invalidation(
-				/** @type {Derived} */ (reaction),
-				effect,
-				depth + 1
-			);
+			schedule_possible_effect_self_invalidation(/** @type {Derived} */ (reaction), effect, false);
 		} else if (effect === reaction) {
-			if (depth === 0) {
+			if (root) {
 				set_signal_status(reaction, DIRTY);
 			} else if ((reaction.f & CLEAN) !== 0) {
 				set_signal_status(reaction, MAYBE_DIRTY);
@@ -458,6 +454,8 @@ export function update_reaction(reaction) {
 		if (
 			is_runes() &&
 			untracked_writes !== null &&
+			!untracking &&
+			deps !== null &&
 			(reaction.f & (DERIVED | MAYBE_DIRTY | DIRTY)) === 0
 		) {
 			for (i = 0; i < /** @type {Source[]} */ (untracked_writes).length; i++) {