idea

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

@@ -93,7 +93,8 @@ function create_effect(type, fn, sync) {
 		parent: is_root ? null : current_effect,
 		prev: null,
 		teardown: null,
-		transitions: null
+		transitions: null,
+		version: 0
 	};
 
 	if (DEV) {

packages/svelte/src/internal/client/reactivity/types.d.ts

@@ -3,6 +3,8 @@ import type { ComponentContext, Dom, Equals, TransitionManager } from '#client';
 export interface Signal {
 	/** Flags bitmask */
 	f: number;
+	/** Write version */
+	version: number;
 }
 
 export interface Value<V = unknown> extends Signal {
@@ -12,8 +14,6 @@ export interface Value<V = unknown> extends Signal {
 	equals: Equals;
 	/** The latest value for this signal */
 	v: V;
-	/** Write version */
-	version: number;
 }
 
 export interface Reaction extends Signal {

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

@@ -180,14 +180,11 @@ export function check_dirtiness(reaction) {
 					if (!dependency.reactions?.includes(reaction)) {
 						(dependency.reactions ??= []).push(reaction);
 					}
+				}
 
-					if (dependency.version > /** @type {import('#client').Derived} */ (reaction).version) {
+				if (dependency.version > reaction.version) {
 					is_dirty = true;
 				}
-				} else if ((reaction.f & DIRTY) !== 0) {
-					// `signal` might now be dirty, as a result of calling `check_dirtiness` and/or `update_derived`
-					return true;
-				}
 			}
 		}
 
@@ -451,6 +448,8 @@ export function execute_effect(effect) {
 		execute_effect_teardown(effect);
 		var teardown = execute_reaction_fn(effect);
 		effect.teardown = typeof teardown === 'function' ? teardown : null;
+
+		effect.version = increment_version();
 	} catch (error) {
 		handle_error(/** @type {Error} */ (error), effect, current_component_context);
 	} finally {